Qing Guo He

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Organization: Chinese Academy of Sciences
Department: Shanghai Institute of Microsystem and Information Technology
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TOPICS

Co-reporter:Pengcheng Wu;Qingguo He;Defeng Zhu;Haibo Jiang;Zinuo Jiao;Yu Zhang;Wei Xu;Yanyan Fu;Huimin Cao;Jiangong Cheng
Analytical Methods (2009-Present) 2017 vol. 9(Issue 25) pp:3804-3809
Publication Date(Web):2017/06/30
DOI:10.1039/C7AY00961E
Volatile organic amine vapors exist in various areas, which can cause a series of harmful effects on environment and human life. Thus, the detection of organic amine vapors with sensitivity and selectivity is greatly needed. This study reports a simple, low-cost, selective and sensitive fluorescence detection of trace organic amine vapors based on CH3NH3PbBr3 (MAPbBr3) nanoplates (NPs) and nanowires (NWs). Upon exposure to organic amines vapors, the fluorescence of MAPbBr3 was strikingly and quickly attenuated (<4 s), and the color of MAPbBr3 changed from yellow to white for some of the organic amines (depending on the R group of R-NHx). This change was rooted in the change of the crystal structure of MAPbBr3 after contacted with different amines. We believe that this result is not only a great advancement in the trace detection of organic amine vapors but is also equally important for fundamental research of organometal halide perovskites.
Co-reporter:Xiangtao Zhang;Defeng Zhu;Yanyan Fu;Qingguo He;Huimin Cao;Wei Li;Jiangong Cheng
Journal of Materials Chemistry C 2017 vol. 5(Issue 8) pp:2114-2122
Publication Date(Web):2017/02/23
DOI:10.1039/C6TC05642C
Inspired by the wide application of whispering gallery mode (WGM) resonance in the field of photonics, a robust sensing platform made of a hollow-shell silica microsphere was proposed and employed for the detection of low vapour pressure explosives such as nitrate ester and hexogen (RDX). The fluorescent sensory materials were synthesized by the organo-functionalization of intact hollow silica microspheres with two rationally designed pyrene derivatives as sensing units. The sensing films of fluorescent microspheres (NPC-Py-SiO2 and TPA-Py-SiO2) made by solid phase transfer method displayed 92% quenching efficiency towards ethylene glycol dinitrate (EGDN) and an 80% sensing response to nitroglycerin (NG) within 300 seconds. In addition, the quenching efficiency and fluorescent intensity of the dye-functionalized microspheres were greatly enhanced by over 900% and 300% compared with their corresponding fluorophores (NPC-Py and TPA-Py), along with superior stability for practical use. Furthermore, the amplified fluorescent intensity and sensitivity were in accordance with theoretical simulation, which proved the WGM resonance of closely stacked silica microspheres. This study enlarged the application of resonant cavities based on size-controlled and functionalized microspheres by a facile preparation method, providing an agile sensing platform for trace explosives and other chemical species with excellent performance.
Co-reporter:Yu Zhang;Zinuo Jiao;Wei Xu;Yanyan Fu;Defeng Zhu;Jiaqiang Xu;Qingguo He;Huimin Cao;Jiangong Cheng
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 10) pp:3790-3797
Publication Date(Web):2017/05/15
DOI:10.1039/C7NJ00851A
As the most important starting material and degradation product of peroxide explosives, H2O2 is considered as a signature compound for peroxide-based explosives. A new probe, (2-(2,6-bis((E)-2-(10-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)anthracen-9-yl)vinyl)-4H-pyran-4-ylidene)malononitrile) (AVPM), for both chromophoric/fluorometric detection of H2O2 was designed and synthesized. AVPM emitted a long wavelength emission from its intramolecular charge transfer (ICT) and hence its absorption was expanded to the visible region. The response rate and sensitivity of AVPM for H2O2 detection were tremendously improved (91% of the fluorescence was quenched within 2 min for H2O2) by adding triethylamine (TEA) into the probe solution. And the solution color changed from yellow to blue. A detection limit down to 17.58 nM is remarkably achieved. These features lead to a new chromophoric/fluorometric probe for H2O2 detection and make it an ideal candidate for chemical detection and analysis in public safety and environmental monitoring.
Co-reporter:Yanyan Fu, Junjun Yao, Wei Xu, Tianchi Fan, Zinuo Jiao, Qingguo He, Defeng Zhu, Huimin Cao, and Jiangong Cheng
Analytical Chemistry 2016 Volume 88(Issue 10) pp:5507
Publication Date(Web):April 20, 2016
DOI:10.1021/acs.analchem.6b01057
The organic thin-film fluorescence probe, with the advantages of not polluting the analyte and fast response, has attracted much attention in explosive detection. Different with nitro explosives, the peroxide-based explosives are hardly to be detected because of their poor ultraviolet absorption and lack of an aromatic ring. As the signature compound of peroxide-based explosives, H2O2 vapor detection became more and more important. Boron ester or acid is considered to be a suitable functional group for the detection of hydrogen peroxide due to its reliable reactive activity. Its only drawback lies on its slow degradation velocity. In this work, we try to introduce some functional group to make the boron ester to be easily oxidized by H2O2. Herein, 4-(phenyl(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)amino)benzaldehyde (OTB) was synthesized and its imine derivatives, OTBXAs, were easily obtained just by putting OTB films in different primary amines vapors. OTBXAs show fast deboronation velocity in H2O2 vapor compared with OTB. The complete reaction time of (E)-N-phenyl-4-((propylimino)methyl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)aniline (OTBPA) was even shortened 40 times with a response time of seconds. The detection limit for H2O2 vapor was as low as 4.1 parts per trillion (ppt). Further study showed that it is a general approach to enhance the sensing performance of borate to hydrogen peroxide (H2O2) vapor by introducing an imine into an aromatic borate molecule via a solid/vapor reaction.
Co-reporter:Junjun Yao, Yanyan Fu, Wei Xu, Tianchi Fan, Yixun Gao, Qingguo He, Defeng Zhu, Huimin Cao, and Jiangong Cheng
Analytical Chemistry 2016 Volume 88(Issue 4) pp:2497
Publication Date(Web):January 18, 2016
DOI:10.1021/acs.analchem.5b04777
Sarin, used as chemical warfare agents (CWAs) for terrorist attacks, can induce a number of virulent effects. Therefore, countermeasures which could realize robust and convenient detection of sarin are in exigent need. A concise charge-transfer colorimetric and fluorescent probe (4-(6-(tert-butyl)pyridine-2-yl)-N,N-diphenylaniline, TBPY-TPA) that could be capable of real-time and on-site monitoring of DCP vapor was reported in this contribution. Upon contact with DCP, the emission band red-shifted from 410 to 522 nm upon exposure to DCP vapor. And the quenching rate of TBPY-TPA reached up to 98% within 25 s. Chemical substances such as acetic acid (HAc), dimethyl methylphosphonate (DMMP), pinacolyl methylphosphonate (PAMP), and triethyl phosphate (TEP) do not interfere with the detection. A detection limit for DCP down to 2.6 ppb level is remarkably achieved which is below the Immediately Dangerous to Life or Health concentration. NMR data suggested that a transformation of the pyridine group into pyridinium salt via a cascade reaction is responsible for the sensing process which induced the dramatic fluorescent red shift. All of these data suggest TBPY-TPA is a promising fluorescent sensor for a rapid, simple, and low-cost method for DCP detection, which could be easy to prepare as a portable chemosensor kit for its practical application in real-time and on-site monitoring.
Co-reporter:Yu Zhang, Yan-Yan Fu, De-Feng Zhu, Jia-Qiang Xu, Qing-Guo He, Jian-Gong Cheng
Chinese Chemical Letters 2016 Volume 27(Issue 8) pp:1429-1436
Publication Date(Web):August 2016
DOI:10.1016/j.cclet.2016.05.019
The detection of peroxide explosives (PEs) has attracted considerable attention all over the world in global security owing to their simple preparation, poor chemical stability and easy decomposition. In recent years, great efforts have been devoted to developing organic fluorescence sensors for detecting the PEs because of their fast response, high sensitivity and high selectivity. In this short review, we firstly discuss the sensing mechanisms for fluorescence based the PEs detection. Next, we reviewed recent progress of PE probes in the nearly 5 years and the design strategies of the material structures to enhance the sensitivity or selectivity, such as conjugated polymers and assembled nanoparticles.With increasing development of organic function materials, fluorescence sensors have caused considerable attention in detecting the peroxide explosives (PEs) in global security because of their fast response, high sensitivity and high selectivity. This short review will focus on current advances in rational design of function materials for fluorescence-based explosive sensing and progress in sensing mechanism and properties research.
Co-reporter:Wei Xu, Yanyan Fu, Junjun Yao, Tianchi Fan, Yixun Gao, Qingguo He, Defeng Zhu, Huimin Cao, and Jiangong Cheng
ACS Sensors 2016 Volume 1(Issue 8) pp:1054
Publication Date(Web):July 27, 2016
DOI:10.1021/acssensors.6b00366
The reactivity of most Intramolecular Charge Transfer (ICT) based probes in the film state is much poorer than that in solution, due to the serious solid state aggregation of the large polarity molecules. In this contribution, an efficient method for activating the aggregation state reactivity of ICT based probes has been developed. Multiple hydrogen bonds formed by the oxime group, together with the phenol anion, could activate the aggregation state reactivity of the oxime group. By enhancing frontier orbital energy level, and constructing porous film structure, the probe becomes more compatible for highly efficient vapor phase reaction. In application, the TOP-I film can distinguish different organic phosphates with significant fluorescence change. The detection limit for diethyl chloro phosphate (DCP) is 1.2 ppb, lower than the Immediately Dangerous to Life and Health (IDLH) level of Sarin. Such a reactivity activating strategy can be extended to detect other harmful vapors by inducing suitable functional groups as the acceptor of the ICT system. Furthermore, with the increasing importance of green chemistry, the method may be beneficial for applications in solvent-free reactions.Keywords: aggregation state reactivity; fluorescence detection; intramolecular charge transfer; multiple hydrogen bonds; warfare agents
Co-reporter:Tianchi Fan, Wei Xu, Junjun Yao, Zinuo Jiao, Yanyan Fu, Defeng Zhu, Qingguo He, Huimin Cao, and Jiangong Cheng
ACS Sensors 2016 Volume 1(Issue 3) pp:312
Publication Date(Web):January 19, 2016
DOI:10.1021/acssensors.5b00293
Solid-state fluorescence probes, without the disadvantages of the existing probe in solution or any pretreatment needed for the analytes, are in great need for the detection of abused drugs. The abused drugs exist as salts, which have low reactivity and volatility, so there is a big challenge for the detection using the solid fluorescence sensing method. In this work, for the first time, a simple, rapid, sensitive, and selective solid-state fluorescence probe—an intramolecular dimer of eight benzyl alcohol-substituted fluorenes bridged by a 1,6-hexanyl unit (8BA-2F)—has been designed, synthesized, and used in a contact mode for ketamine and methylamphetamine detection without the pretreatment of the drugs. Upon contact with the drugs in different concentrations, the emission will show a different emission color, which could be visible with the naked eye. Even 50 pg/cm2 ketamine could be detected by the naked eye. Theoretical calculation indicates that there is strong hydrogen bonding interaction between the eight −PhCH2OH and −NH2+–, which induced a large steric configuration change of 8BA-2F, resulting in significantly enhanced fluorescence at 398 nm, while the emission at 463 nm showed less change. Therefore, the ratio change of the emission band peaked at 398 and 463 nm, triggered by a different amount of the drug molecules resulting in a different emission color. Together with the characteristics of the dimer such as multiple active sites, moderate interaction force, high steric hindrance related to easy penetration of the drug, the probe showed a sensitive, selective, and rapid sensing performance.Keywords: fluorescence probe; intramolecular dimer; ketamines; methylamphetamine; pictogram
Co-reporter:Yanyan Fu;Wei Xu;Qingguo He;Jiangong Cheng
Science China Chemistry 2016 Volume 59( Issue 1) pp:3-15
Publication Date(Web):2016 January
DOI:10.1007/s11426-015-5498-3
There are great needs for real-time detection of volatile organic amines (VOA) through low-cost detection methods in public health, food safety, and environmental monitoring area. Organic thin-film fluorescent probe (OTFFP) is expected to become a new and efficient means of detecting VOA because of its fast response, high sensitivity, no contamination to the analyte and ease to prepare a portable instrument. Compared with the mature detection methods in solution, research on solid fluorescence sensing has been less studied. In this article, we review recent progress in OTFFP research for VOA vapour. We mainly focus on the new fluorescent sensing mechanisms applied in solid state in recent years and the design principle of probes for different types of organic amines (such as primary amine, secondary amine, tertiary amine and aromatic amine). We also review the material structures of these probes and the strategies to enhance their sensitivity or selectivity.
Co-reporter:Yixun Gao, Wei Xu, Defeng Zhu, Lei Chen, Yanyan Fu, Qingguo He, Huimin Cao and Jiangong Cheng  
Journal of Materials Chemistry A 2015 vol. 3(Issue 9) pp:4820-4826
Publication Date(Web):26 Nov 2014
DOI:10.1039/C4TA05704J
Compared with nitroaromatic explosive detection, nitrate ester explosive detection has not received considerable attention possibly due to the absence of an aromatic ring and their difficulty in being detected. An eight triphenylamino-pyrenyl substituted POSS (P8PT) was designed as a sensory material. POSS was chosen as the skeleton due to its nano structure, multiple reactive sites, structural similarity with nitrate esters and high thermal stability, which will contribute to large surface area induced high sensitivity, tunable sensory units number, stronger interaction force with nitrate esters and high stability. For comparison, triphenylamino-pyrene (Py-TPA) (without POSS), one and three Py-TPA substituted POSS were also synthesized and characterized. Their chemical structures, photophysical and electrochemical properties show that P8PT has a 3-D symmetrical spatial conformation, higher molar extinction coefficient, higher area-to-volume ratio, multiple exciton transfer path, and matched energy level with nitrate ester explosives, which will all contribute to highly efficient sensing performance and efficient selectivity for the detection of nitrate ester explosives such as nitroglycerin (NG). The fluorescence of the P8PT film is 63% quenched upon exposure to a saturated vapor of NG for 50 s and 92% quenched for 300 s at room temperature due to photoinduced electron transfer between the probe and NG. These results reveal that P8PT is suitable for preparing a highly sensitive and efficient thin-film device for detecting nitrate esters.
Co-reporter:Wei Xu, Yanyan Fu, Yixun Gao, Junjun Yao, Tianchi Fan, Defeng Zhu, Qingguo He, Huimin Cao and Jiangong Cheng  
Chemical Communications 2015 vol. 51(Issue 54) pp:10868-10870
Publication Date(Web):20 May 2015
DOI:10.1039/C5CC03406J
A simple, highly stable, sensitive and selective fluorescent system for peroxide explosives was developed via an aromatic aldehyde oxidation reaction. The high efficiency arises from its higher HOMO level and multiple H-bonding. The sensitivity is obtained to be 0.1 ppt for H2O2 and 0.2 ppb for TATP.
Co-reporter:Yanyan Fu, Junjun Yao, Wei Xu, Tianchi Fan, Qingguo He, Defeng Zhu, Huimin Cao and Jiangong Cheng  
Polymer Chemistry 2015 vol. 6(Issue 12) pp:2179-2182
Publication Date(Web):27 Jan 2015
DOI:10.1039/C4PY01793E
An ultrasensitive and reversible “fingerprint” fluorescent probe has been developed by embedding multiple reactive groups onto one conjugated polymer backbone. The probe can be used for the simultaneous detection of primary aliphatic amines, secondary aliphatic amines, aromatic amines and their mixtures.
Co-reporter:Yuerong Wang, Yixun Gao, Lei Chen, Yanyan Fu, Defeng Zhu, Qingguo He, Huimin Cao, Jiangong Cheng, Runsheng Zhang, Shuiqing Zheng and Songmao Yan  
RSC Advances 2015 vol. 5(Issue 7) pp:4853-4860
Publication Date(Web):05 Dec 2014
DOI:10.1039/C4RA12966K
A fluorescent diphenylfluorene-pyrenyl copolymer with dibenzothiophene-S,S-dioxide (SO) and adamantane units has been successfully synthesized via a Suzuki–Miyaura cross-coupling reaction. After studying the sensing properties of a series of diphenylfluorene-pyrenyl materials towards TNT vapor, it was found that the dibenzothiophene-S,S-dioxide (SO) units introduced into the diphenylfluorene-pyrenyl copolymers can simultaneously enhance the photostability and sensing performance of the fluorescent sensing materials. This simple strategy can be used as a promising approach for the development of fluorescent conjugated sensing materials.
Co-reporter:Junjun Yao, Yanyan Fu, Wei Xu, Tianchi Fan, Qingguo He, Defeng Zhu, Huimin Cao and Jiangong Cheng  
RSC Advances 2015 vol. 5(Issue 32) pp:25125-25131
Publication Date(Web):04 Mar 2015
DOI:10.1039/C5RA00363F
Volatile organic amines can induce a number of deleterious effects on the ecological environment and human health. A highly efficient detection method is in exigent need. A series of fluorescent probes with trifluoroacetyl as the reactive unit and aromatic moieties including anthracene (ANT–TFA), pyrene (PY–TFA) and triphenylamine (TPA–TFA) unit as fluorophores have been designed for highly reversible, sensitive and efficient amine detection in this contribution. The aromatic unit could significantly tune the reactivity and fluorescent property of the probe. A rapid, reversible and sensitive (ppm to sub-ppb) probe could be realized for differentiating primary and secondary alkyl amines and aniline. Materials Studio was used to understand the reactivity and sensing performance difference. The findings reported herein can greatly advance the real-time monitoring and differentiating of trace organic amines.
Co-reporter:Lei Chen, Yixun Gao, Yanyan Fu, Defeng Zhu, Qingguo He, Huimin Cao and Jiangong Cheng  
RSC Advances 2015 vol. 5(Issue 38) pp:29624-29630
Publication Date(Web):18 Mar 2015
DOI:10.1039/C5RA02472B
The vapor of peroxide explosives (PEs) is difficult to detect using fluorescent probes because PEs are not typical quenching agents, not having nitro groups or aromatic units that can easily interact with electron-rich probes. Three borate ester endcapped pyrenyl–fluorene copolymers were reported for the detection of PEs, including a hyperbranched polymer (S1) and two linear polymers with borate esters on fluorenyl (S2) or pyrenyl (S3) units. It was found that the hyperbranched polymer S1 has greater steric hindrance, more external borate ester groups, higher HOMO level and higher fluorescence quantum yield, which give it higher sensitivity to H2O2 vapor than S2 and S3. To further amplify the sensing performance toward H2O2 vapor, a polymer/ZnO nanorod array composite was used, exploiting the catalytic ability and high area to volume ratio of the ZnO nanorod array. The fluorescence of the S1 film is quenched by ∼60% and ∼30% under saturated vapor of H2O2 and TATP, respectively, for 300 s at room temperature, and the detection limit for H2O2 is estimated to be 1.6 ppb. These results reveal that the S1/ZnO nanorod array composite is very promising for the preparation of a highly sensitive fluorescence device for detecting the vapor of peroxide explosives.
Co-reporter:Liqi Shi, Yanyan Fu, Chao He, Defeng Zhu, Yixun Gao, Yuerong Wang, Qingguo He, Huimin Cao and Jiangong Cheng  
Chemical Communications 2014 vol. 50(Issue 7) pp:872-874
Publication Date(Web):13 Nov 2013
DOI:10.1039/C3CC48299E
A new rapid and catalyst-free solid/vapor reaction between benzylidenemalonate/benzylidenemalononitrile and primary alkyl amines was found. With these as sensory units of fluorescent polymers, probes for primary amine vapor with high sensitivity and selectivity were developed.
Co-reporter:Lei Chen, Yixun Gao, Yuerong Wang, Chao He, Defeng Zhu, Qingguo He, Huimin Cao, and Jiangong Cheng
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 11) pp:8817
Publication Date(Web):April 22, 2014
DOI:10.1021/am501543f
Compared with nitroaromatic explosives detection, nitrate esters are far from wide attention possibly because of their shortage of aromatic ring and difficulty in being detected. Three fluorescent chemical probes for trace nitrate ester detection: an intramolecular dimer (P3) of 8-pyrenyl-substituted fluorenes bridged by a 1,6-hexanyl unit as well as its counterparts 2PR-F (P1) and 2PR-Cz (P2) has been synthesized and characterized. Their chemical structures and photophysical and electrochemical properties show that the dimer P3 film has a higher molar extinction coefficient, larger steric hindrance, higher area-to-volume ratio, and matching energy level with nitrate ester explosives, which contributes to higher sensitivity and moderate selectivity for sensing of nitrate ester explosives such as nitroglycerin (NG). The fluorescence of the P3 film is rapidly about 90% quenched upon exposure to a saturated vapor of NG for 50 s and almost 100% quenched for 300 s at room temperature due to photoinduced electron transfer between the probe and analyte. In addition, a very sensitive, rapid, simple, and low-cost surface-sensing method by disposable filter-paper-based test strips is demonstrated. The contact-mode approach exhibits a detection limit as low as 0.5 fg/cm2 for NG. These results reveal that the multiple-pyrenyl-unit-substituted fluorene dimer P3 is suitable for preparing a highly sensitive and efficient thin-film device for detecting nitrate esters.Keywords: femtogram; fluorescence quenching; fluorescent probe; nitroglycerin; surface sensing;
Co-reporter:Changqing Ye, Bin Sun, Xiaomei Wang, Jiawei Yang, Ping Ding, Saijiang Zhu, Qingguo He, Zuoqin Liang, Xutang Tao
Dyes and Pigments 2014 Volume 102() pp:133-141
Publication Date(Web):March 2014
DOI:10.1016/j.dyepig.2013.10.010
•A series of chromophores were synthesized with acceptors of pyridinylbenzothiadiazole.•The chromophores present two-photon absorption cross-section from 121 to 254 GM.•The two-photon fluorescence quenching to the metal ions is sensitive.•Showing potential application in heavy metal detecting or environmental sensor.New two-photon up-conversion fluorescence (TPF) sensors, containing triphenylamine or carbazole as donor (D) and flanked pyridinylbenzothiadiazole as acceptor (A) to form D–π–An(n=1, 2 or 3) architecture, were synthesized and characterized. The investigation correlated molecular structure (acceptor number) with linear absorption, one-photon fluorescence (OPF) and two-photon fluorescence (TPF) detecting Cu2+, Ni2+, Hg2+ and Ag+ was carried out. Sensors containing more acceptor groups were found to exhibit greater sensitivity to both absorption and fluorescence detection. A comparison between OPF and TPF responses to the given metal ion (Cu2+) showed that the sensitivity of TPF quenching is larger than that of OPF quenching. This strongly supports the idea that pyridinylbenzothiadiazole-based chromophores with more acceptor groups possess potential application as two-photon up-conversion sensors.
Co-reporter:Yanyan Fu, Qingguo He, Defeng Zhu, Yuerong Wang, Yixun Gao, Huimin Cao and Jiangong Cheng  
Chemical Communications 2013 vol. 49(Issue 96) pp:11266-11268
Publication Date(Web):10 Oct 2013
DOI:10.1039/C3CC46571C
A new reaction based fluorescence turn-off strategy for detection of secondary amines was developed. The probe shows fast response and high selectivity to secondary amines in solution/film at sub-ppm levels through chromogenic and fluorescent dual-mode signal changes.
Co-reporter:Kang-Yi Hua, Chang-Min Deng, Chao He, Li-Qi Shi, De-Feng Zhu, Qing-Guo He, Jian-Gong Cheng
Chinese Chemical Letters 2013 Volume 24(Issue 7) pp:643-646
Publication Date(Web):July 2013
DOI:10.1016/j.cclet.2013.04.033
We report the first use of organic semiconductors (OSCs)-coated PAN nanofibrous mats as highly responsive fluorescence quenching-based chemosensors for 2,4,6-trinitrotoluene (TNT) and H2O2 detection in vapor phase. Conjugated polymers, poly(triphenylaminealt-biphenylene vinylene) (TPA-PBPV), and small organic molecules, 1-boronic-ester pyrene and 1,6-bisboron-ester pyrene, were coated onto the nanofibers fabricated by electrospinning. By introducing the nanofibers structure, a 9-fold fluorescence intensity enhancement and a 14-fold sensitivity enhancement were achieved, which could be attributed to its high area-to-volume ratio, excellent gas permeability, and more importantly, the evanescent-wave effect occurred once the diameters of the fibers were small enough. Since the organic semiconductors coated onto the nanofibrous mats could be replaced by other functional materials, the nanofibers-enhanced detection strategies could be extended to more general domains including chemical and environmental detection.We report the first use of organic semiconductors (OSCs)-coated PAN nanofibrous mats as highly responsive fluorescence quenching-based chemosensors for 2,4,6-trinitrotoluene (TNT) and H2O2 detection in vapor phase.
Co-reporter:Yanyan Fu, Liqi Shi, Defeng Zhu, Chao He, Dan Wen, Qingguo He, Huimin Cao, Jiangong Cheng
Sensors and Actuators B: Chemical 2013 180() pp: 2-7
Publication Date(Web):
DOI:10.1016/j.snb.2011.10.031
Co-reporter:Lin Dong, Changmin Deng, Chao He, Liqi Shi, Yanyan Fu, Defeng Zhu, Huimin Cao, Qingguo He, Jiangong Cheng
Sensors and Actuators B: Chemical 2013 180() pp: 28-34
Publication Date(Web):
DOI:10.1016/j.snb.2011.11.046
Co-reporter:Liqi Shi, Chao He, Defeng Zhu, Qingguo He, Yang Li, Yan Chen, Yuxi Sun, Yanyan Fu, Dan Wen, Huimin Cao and Jiangong Cheng  
Journal of Materials Chemistry A 2012 vol. 22(Issue 23) pp:11629-11635
Publication Date(Web):05 Apr 2012
DOI:10.1039/C2JM30933E
A series of benzothiadiazole-pyridine branched triphenylamine derivatives TPA1BP, TPA2BP and TPA3BP have been designed and synthesized to sense aniline vapor with distinguished sensitivity, selectivity and repeatability via photoinduced electron transfer (PET). Suitable energy levels ensure the high selectivity to aniline for all three sensory materials. However, the aggregations of the three materials in the film state on a quartz substrate increase along with the branches, which highly deteriorate the sensing performance for less efficient fluorescence, lower contact area and inferior vapor penetration. The oriented ZnO nanorod array is introduced as the substrate to eliminate the aggregation and enhance the sensing performance, because of its high surface-to-volume ratio and 3D structure. Therefore, the cooperative effect that the sensing performance of TPAnBP increases with the number of branches could be observed; fluorescence intensities of the films on the nano-substrate are 34%, 45% and 54% quenched for TPA1BP, TPA2BP and TPA3BP, respectively, after exposure to 300 ppm aniline vapor for less than 5 s. Moreover, the fluorescences of all three sensory materials are almost 100% recovered by eluting with fresh air for 20 s and could be reused immediately. The detection limits are predicted to be 1 ppm for TPA1BP, 100 ppb for TPA2BP and 1 ppb for TPA3BP according to the fitted plot, demonstrating a significant cooperative effect of the molecular branches.
Co-reporter:Chao He, Defeng Zhu, Qingguo He, Liqi Shi, Yanyan Fu, Dan Wen, Huimin Cao and Jiangong Cheng  
Chemical Communications 2012 vol. 48(Issue 46) pp:5739-5741
Publication Date(Web):17 Apr 2012
DOI:10.1039/C2CC31386C
A new strategy capable of detecting explosive peroxide vapor via deboronation reaction induced fluorescence quenching has been developed. Using ordered assembly arrays of ZnO nanorods as catalyzing substrates, the deboronation reaction was 42 times faster than that on quartz substrates, which resulted in a very fast response and high sensitivity.
Co-reporter:D. Wen, Y.Y. Fu, L.Q. Shi, C. He, L. Dong, D.F. Zhu, Q.G. He, H.M. Cao, J.G. Cheng
Sensors and Actuators B: Chemical 2012 Volume 168() pp:283-288
Publication Date(Web):20 June 2012
DOI:10.1016/j.snb.2012.04.024
Fluorescent sensors with high sensitivity, selectivity and fast response for trace detection of methamphetamine (MA) have been rarely reported. Herein, three fluorene-based sensory materials were synthesized and used for MA detection. The fine structural tuning could control both the energy level and bonding force to MA. Their fluorescence quenching responses to different amines were due to photo-induced electron transfer (PET) from MA donor to the photoexcited state of sensing polymers. Meanwhile, the fine-tuning of the bonding force resulted in different sensitivity and selectivity of the polymers. Among them, polymer with benzothiadiazole showed the best selectivity and sensitivity to MA vapor with a detection limit of 180 ppb. And ∼20% fluorescence could be quenched/recovered within 2 s upon exposure to MA and air in sequence.
Co-reporter:Xin Meng, Qing Guo He, Hui Min Cao, Jian Gong Cheng
Chinese Chemical Letters 2011 Volume 22(Issue 6) pp:725-728
Publication Date(Web):June 2011
DOI:10.1016/j.cclet.2010.12.024
A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups (BPY-HPV) was synthesized. BPY-HPV was highly sensitive to metal ions (Cu2+, Ni2+) for the strong coordination interaction (Ksv at the order of 107 mol−1 L) monitored by fluorescence spectroscopy. Moreover, by hydrogen bonds and charge transfer interaction, BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH2Cl2 (Ksv ∼ 106 mol−1 L) or film.
Co-reporter:Chao He, Qingguo He, Changmin Deng, Liqi Shi, Yanyan Fu, Huimin Cao, Jiangong Cheng
Synthetic Metals 2011 Volume 161(3–4) pp:293-297
Publication Date(Web):February 2011
DOI:10.1016/j.synthmet.2010.11.038
Three different poly{9,9-bis[6′(–NHBoc, –NH3+ and –NH2)hexyl]fluorene}s (PF-NHBoc, PF-NH3+ and PF-NH2) have been synthesized and characterized. Both UV–Vis and fluorescence spectroscopic results supported the interaction between the polyfluorenes and Methamphetamine Hydrochloride (MAPA) was derived from the different terminals of hexyl side chains. Among the three polyfluorenes, PF-NH2 exhibited the best sensory response to Methamphetamine Hydrochloride (MAPA) in THF arising from its –NH2 terminals. The fluorescence of PF-NH2 was immediately quenched once the MAPA was added, and the detection limit of MAPA was determined to be ∼25 ng/mL. Fluorescence quenching experiments of PF-NH2 by NH4Cl and other metal ions confirmed that electrostatic interaction should make contributions to the quenching behavior, in addition, upward non-linear curvature and much higher quenching constant (Ksv) in the Stern–Volmer plots for MAPA suggested some other interactions such as hydrophobic or/and hydrogen-bonding interactions dominated the analyte-induced aggregation, and such hydrophobic interaction was responsible for the sensitive selectivity. The fluorescent quenching experiments upon adding other drugs such as Pethidine Hydrochloride (PTD) and Ephedrine Hydrochloride (EPD) confirmed such selectivity, especially under the high concentration of the Stern–Volmer plots. The high sensitivity, selectivity, and its simple and fast character, made it a new and effective way for drug detection.
Co-reporter:Defeng Zhu, Qingguo He, Qing Chen, Yanyan Fu, Chao He, Liqi Shi, Xin Meng, Changmin Deng, Huimin Cao, and Jiangong Cheng
ACS Nano 2011 Volume 5(Issue 6) pp:4293
Publication Date(Web):May 23, 2011
DOI:10.1021/nn103211d
Nanomaterials and -structures have attracted much attention owing to their applications to ultrasensitive nanodevices. In this work, ordered assembly arrays of ZnO nanorods have been hydrothermally fabricated and used as optical substrates of fluorescence sensors for toxic vapors. The unique fastigiate nanorod assembly combines merits of single fibers and clusters, possessing identical orientation, large surface-to-volume ratio, evanescent transmission, and evanescent coupling. As coated on the assembly arrays, different sensing materials all generated amplified spontaneous emission (ASE) action such that the fluorescence intensity of the narrowed spectrum was 52.4-fold enhanced. Results of sensing experiments indicate that sensors based on the assembly arrays displayed 100% elevated normalized quenching rate and several times longer full-load time compared with reference sensors. This work provides a facile method to fabricate secondary structures of 1D rigid material and presents a new way to design highly sensitive optic sensors. Furthermore, evanescent excitation caused ASE action of fluorescent organics, and the correlative sensitivity gain is of interest in both theoretical research and the applications field.Keywords: AFAs; assembly; evanescent wave; fluorescence; sensor; vapor; ZnO nanorod
Co-reporter:Chao He, Qingguo He, Changmin Deng, Liqi Shi, Defeng Zhu, Yanyan Fu, Huimin Cao and Jiangong Cheng  
Chemical Communications 2010 vol. 46(Issue 40) pp:7536-7538
Publication Date(Web):15 Sep 2010
DOI:10.1039/C0CC01972K
A sensitive, selective, reversible, and easy performance way of detecting electron donating volatile amines such as abused drug methamphetamine (MAPA) has been developed.
Co-reporter:Chao He, Qingguo He, Qing Chen, Liqi Shi, Huimin Cao, Jiangong Cheng, Changmin Deng, Tong Lin
Tetrahedron Letters 2010 Volume 51(Issue 9) pp:1317-1321
Publication Date(Web):3 March 2010
DOI:10.1016/j.tetlet.2009.12.136
Two intramolecular dimmers of 4-, 8-pyrenyl-substituted fluorenes bridged by 1,6-hexanyl unit have been synthesized. They showed very strong fluorescent emission with the emission peak at around 450 nm and fluorescence efficiency as high as ∼0.9. The absorption spectra also had high extinction coefficients. The cyclic voltammetric curves showed that they can be used as electron-donating materials. The DSC results suggested the dimmers have higher glass transition temperature. It was also found that these novel dimmers can self-organize into spherical particles from the solutions due to evaporation of the solvent.Two intramolecular fluorene dimmers (structure as illustrated) have been synthesized, and they both have shown very high fluorescent efficiency, can self-organize into spherical particles from solutions due to evaporation of the solvent.
Co-reporter:Changmin Deng, Pei Gong, Qingguo He, Jiangong Cheng, Chao He, Liqi Shi, Defeng Zhu, Tong Lin
Chemical Physics Letters 2009 Volume 483(4–6) pp:219-223
Publication Date(Web):1 December 2009
DOI:10.1016/j.cplett.2009.10.060
Well-aligned nanofibers were prepared from a conjugated polymer, poly(triphenylamine-alt-biphenylene vinylene) (TPA-PBPV), using a solution-assisted template wetting technique. TPA-PBPV was also coated on the surface of electrospun polyacrylonitrile (PAN) nanofiber nonwoven membrane. The extremely large surface area, highly porous fibrous structure, optical scattering and evanescent-wave guiding effect imparted these one-dimensional (1D) nanofibrous materials with highly improved sensory ability to 2,4,6-trinitrotoluene (TNT) vapors and higher quenching efficiency than that of the neat TPA-PBPV films. The results suggest that nanofibrous structures could be a promising strategy to improve the sensory efficiency of fluorescent chemosensors.The evanescent-wave field profile of nanofiber with 100-nm-diameter, at 400-nm wavelength excitation.
Co-reporter:Yi Yang, Yi Zhou, Qingguo He, Chang He, Chunhe Yang, Fenglian Bai and Yongfang Li
The Journal of Physical Chemistry B 2009 Volume 113(Issue 22) pp:7745-7752
Publication Date(Web):May 11, 2009
DOI:10.1021/jp900362f
Three solution-processable red-emissive organic materials with a hole-transporting unit triphenylamine (TPA) as the core part and a D−π−A bipolar structure as the branch part, TPA-BT (single-branched molecule), b-TPA-BT (bibranched molecule), and t-TPA-BT (tribranched molecule), were synthesized by the Heck coupling reaction. Herein, for the D−π−A push−pull structure, we use TPA as the electron donor, benzothiodiazole (BT) as the electron acceptor, and the vinylene bond as the π-bridge connecting the TPA and BT units. The compounds exhibit good solubility in common organic solvents, benefited from the three-dimensional spatial configuration of TPA units and the branch structure of the molecules. TPA-BT, b-TPA-BT, and t-TPA-BT show excellent photoluminescent properties with maximum emission peaks at ca. 630 nm. High-performance red-emission organic light-emitting diodes (OLEDs) were fabricated with the active layer spin coated from a solution of these compounds. The OLED based on TPA-BT displayed a low turn-on voltage of 2.0 V, a maximum luminance of 12192 cd/m2, and a maximum current efficiency of 1.66 cd/A, which is among the highest values for the solution-processed red-emission OLEDs. In addition, high-performance white-light-emitting diodes (WLEDs) with maximum luminance around 4400 cd/m2 and maximum current efficiencies above 4.5 cd/A were realized by separately doping the three TPA-BT-containing molecules as red emitter and poly(6,6′-bi-(9,9′-dihexylfluorene)- co-(9,9′-dihexylfluorene-3-thiophene-5′-yl)) as green emitter into blue poly(9,9-dioctylfluorene-2,7-diyl) host material with suitable weight ratios.
Co-reporter:Yi Zhou;Qingguo He;Yi Yang;Haizheng Zhong;Chang He;Guangyi Sang;Wei Liu;Chunhe Yang;Fenglian Bai;Yongfang Li
Advanced Functional Materials 2008 Volume 18( Issue 20) pp:3299-3306
Publication Date(Web):
DOI:10.1002/adfm.200800375

Abstract

Strong intermolecular interactions usually result in decreases in solubility and fluorescence efficiency of organic molecules. Therefore, amorphous materials are highly pursued when designing solution-processable, electroluminescent organic molecules. In this paper, a non-planar binaphthyl moiety is presented as a way of reducing intermolecular interactions and four binaphthyl-containing molecules (BNCMs): green-emitting BBB and TBT as well as red-emitting BTBTB and TBBBT, are designed and synthesized. The photophysical and electrochemical properties of the molecules are systematically investigated and it is found that TBT, TBBBT, and BTBTB solutions show high photoluminescence (PL) quantum efficiencies of 0.41, 0.54, and 0.48, respectively. Based on the good solubility and amorphous film-forming ability of the synthesized BNCMs, double-layer structured organic light-emitting diodes (OLEDs) with BNCMs as emitting layer and poly(N-vinylcarbazole) (PVK) or a blend of poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine] and PVK as hole-transporting layer are fabricated by a simple solution spin-coating procedure. Amongst those, the BTBTB based OLED, for example, reaches a high maximum luminance of 8315 cd · m−2 and a maximum luminous efficiency of 1.95 cd · A−1 at a low turn-on voltage of 2.2 V. This is one of the best performances of a spin-coated OLED reported so far. In addition, by doping the green and red BNCMs into a blue-emitting host material poly(9,9-dioctylfluorene-2,7-diyl) high performance white light-emitting diodes with pure white light emission and a maximum luminance of 4000 cd · m−2 are realized.

Co-reporter:Chang He, Qingguo He, Yuanping Yi, Guanglong Wu, Fenglian Bai, Zhigang Shuai and Yongfang Li  
Journal of Materials Chemistry A 2008 vol. 18(Issue 34) pp:4085-4090
Publication Date(Web):21 Jul 2008
DOI:10.1039/B807456A
A new solution processable star-shaped organic molecule S(TPA-BT) has been synthesized for application in organic solar cells (OSCs). The properties and structures of S(TPA-BT) and a related linear molecule L(TPA-BT) were studied, including UV-visible spectroscopy, hole charge mobility, and theoretical calculated geometry and electronic properties. S(TPA-BT) film shows a broader and stronger absorption band in the range of 440–670 nm, lower band gap of 1.86 eV, higher hole mobility of 4.71 × 10−5 cm2V−1 s−1 and better film-forming properties compared with those of L(TPA-BT) film. ITO/PEDOT:PSS/S(TPA-BT) or L(TPA-BT):PCBM/Ba/Al bulk-heterojunction OSCs were fabricated with S(TPA-BT) or L(TPA-BT) as donor material. The power conversion efficiency (PCE) of an OSC based on a blend of S(TPA-BT) and PCBM (1 : 3, w/w) reached 1.33% under A.M. 1.5 illumination, 100 mW cm−2, with a short-circuit current density (JSC) of 4.18 mA cm−2, an open circuit voltage of 0.81 V, and a fill factor of 39%. The PCE of 1.33% and Jsc of 4.18 mA cm−2 are among the highest values reported so far for solution processable OSCs.
Co-reporter:Qing Guo He, Zeng Ze Chu, Gang Tie Lei, An Jun Qin, Hong Zhen Lin, Feng Lian Bai, Jian Gong Cheng, Yong Qiu
Chinese Chemical Letters 2008 Volume 19(Issue 4) pp:431-434
Publication Date(Web):April 2008
DOI:10.1016/j.cclet.2008.02.002
A binaphthyl derivative with pyrene on 3 and 3′ positions was synthesized and characterized via Suzuki coupling reaction. Emission maximum in solution was located at 390 nm with a quantum efficiency of 68% by taking 9,10-diphenyl anthracene as reference, while it is shifted to 450 nm with FWHM of 104 nm resulting from aggregation state in solid film. Glass transition temperature (Tg) and decomposition temperature were measured to be 184 and 447 °C, respectively, by DSC and TGA. Unlike its photoluminescence spectrum, electroluminescent spectrum peaked at about 460 nm and shows a FWHM of 69 nm corresponding to a pure blue emission. The turn-on voltage, luminance and efficiency maximum were 5 V, 2953 cd/m2 and 1.37 cd/A with CIE color coordinate of (0.16, 0.15), in the device structure of ITO/NPB (40 nm)/PY-BN-PY (15 nm)/BPhen (40 nm)/Mg:Ag.
Co-reporter:Qingguo He, Chang He, Yuxi Sun, Hongxia Wu, Yongfang Li, Fenglian Bai
Thin Solid Films 2008 Volume 516(Issue 18) pp:5935-5940
Publication Date(Web):31 July 2008
DOI:10.1016/j.tsf.2007.10.058
A D-π-A-π-D compound 4,7-bis{5′-[4″,4″-N, N-diphenylamino-styryl]thiophen-2′-yl}benzo[1,2,5-thiadiazole] (TPA-BTD-TPA) with triphenylamine (TPA) as electron-donor and benzothiadiazole (BTD) as electron-acceptor and linked via vinyl unit was synthesized and characterized. A stable intramolecular charge-transfer state enabled the molecule to expand the optical absorption band and prevented the occurrence of electron back-donation. Excellent film-forming property made it easy prepare homogeneous film using a spin-coating technique. Suitable energy levels were beneficial for the improvement of photovoltaic device performance. Photovoltaic cell based on TPA-BTD-TPA/[6,6]-phenyl C61-butyric acid methyl ester as a active layer was fabricated, and the optical conversion efficiency was 0.26% under the illumination of AM 1.5 (85 mW/cm2).
Co-reporter:Qing Guo He, Jian Gong Cheng, Feng Lian Bai
Chinese Chemical Letters 2007 Volume 18(Issue 8) pp:920-922
Publication Date(Web):August 2007
DOI:10.1016/j.cclet.2007.05.055
A starburst triphenylamine cored N-vinyl carbazole (V-Cz) branched compound was designed and synthesized via optimized Heck reaction in a yield of 40–60%. Moderate yield came from decomposition of V-Cz and self-coupling of triiodo-triphenylamine. TCz-TPA adopts a highly twisted propeller conformation by molecular mechanical optimization. It is readily soluble for its highly twisted conformation. Transparent and pinhole free films could be easily fabricated by spin-coating for its starburst structure. It emits blue-greenish light in CH2Cl2 peaked at 460 nm with a narrow full-width at half-maximum (FWHM) of 65 nm. As compared, the absorption peaks of the spin-coated film blue shifted and emission peak red shifted to 510 nm with a FWHM of 96 nm.
Co-reporter:Qing Guo He, Xi Peng Guo, Jian Gong Cheng, Feng Lian Bai
Chinese Chemical Letters 2007 Volume 18(Issue 7) pp:820-822
Publication Date(Web):July 2007
DOI:10.1016/j.cclet.2007.04.039
A donor–bridge–donor compound for blue light-emitting with triphenylamine as donor and pentiptycene derivative units as bridge was synthesized via Sonogashira reaction. The chemical structure was confirmed by NMR and MALDI-TOF MS. It emits blue light peaked at 442 nm with a FWHM of 59 nm in CH2Cl2. Fluorescent quantum efficiency in THF is 82% relative to 9,10-diphenylanthracene. A slight hypsochromic shift was found in its drop-cast film. Cyclic voltammetry revealed that it has high HOMO level corresponding to hole transporting character.
Co-reporter:Xiangtao Zhang, Defeng Zhu, Yanyan Fu, Qingguo He, Huimin Cao, Wei Li and Jiangong Cheng
Journal of Materials Chemistry A 2017 - vol. 5(Issue 8) pp:NaN2122-2122
Publication Date(Web):2017/01/30
DOI:10.1039/C6TC05642C
Inspired by the wide application of whispering gallery mode (WGM) resonance in the field of photonics, a robust sensing platform made of a hollow-shell silica microsphere was proposed and employed for the detection of low vapour pressure explosives such as nitrate ester and hexogen (RDX). The fluorescent sensory materials were synthesized by the organo-functionalization of intact hollow silica microspheres with two rationally designed pyrene derivatives as sensing units. The sensing films of fluorescent microspheres (NPC-Py-SiO2 and TPA-Py-SiO2) made by solid phase transfer method displayed 92% quenching efficiency towards ethylene glycol dinitrate (EGDN) and an 80% sensing response to nitroglycerin (NG) within 300 seconds. In addition, the quenching efficiency and fluorescent intensity of the dye-functionalized microspheres were greatly enhanced by over 900% and 300% compared with their corresponding fluorophores (NPC-Py and TPA-Py), along with superior stability for practical use. Furthermore, the amplified fluorescent intensity and sensitivity were in accordance with theoretical simulation, which proved the WGM resonance of closely stacked silica microspheres. This study enlarged the application of resonant cavities based on size-controlled and functionalized microspheres by a facile preparation method, providing an agile sensing platform for trace explosives and other chemical species with excellent performance.
Co-reporter:Wei Xu, Yanyan Fu, Yixun Gao, Junjun Yao, Tianchi Fan, Defeng Zhu, Qingguo He, Huimin Cao and Jiangong Cheng
Chemical Communications 2015 - vol. 51(Issue 54) pp:NaN10870-10870
Publication Date(Web):2015/05/20
DOI:10.1039/C5CC03406J
A simple, highly stable, sensitive and selective fluorescent system for peroxide explosives was developed via an aromatic aldehyde oxidation reaction. The high efficiency arises from its higher HOMO level and multiple H-bonding. The sensitivity is obtained to be 0.1 ppt for H2O2 and 0.2 ppb for TATP.
Co-reporter:Liqi Shi, Yanyan Fu, Chao He, Defeng Zhu, Yixun Gao, Yuerong Wang, Qingguo He, Huimin Cao and Jiangong Cheng
Chemical Communications 2014 - vol. 50(Issue 7) pp:NaN874-874
Publication Date(Web):2013/11/13
DOI:10.1039/C3CC48299E
A new rapid and catalyst-free solid/vapor reaction between benzylidenemalonate/benzylidenemalononitrile and primary alkyl amines was found. With these as sensory units of fluorescent polymers, probes for primary amine vapor with high sensitivity and selectivity were developed.
Co-reporter:Chao He, Defeng Zhu, Qingguo He, Liqi Shi, Yanyan Fu, Dan Wen, Huimin Cao and Jiangong Cheng
Chemical Communications 2012 - vol. 48(Issue 46) pp:NaN5741-5741
Publication Date(Web):2012/04/17
DOI:10.1039/C2CC31386C
A new strategy capable of detecting explosive peroxide vapor via deboronation reaction induced fluorescence quenching has been developed. Using ordered assembly arrays of ZnO nanorods as catalyzing substrates, the deboronation reaction was 42 times faster than that on quartz substrates, which resulted in a very fast response and high sensitivity.
Co-reporter:Yanyan Fu, Qingguo He, Defeng Zhu, Yuerong Wang, Yixun Gao, Huimin Cao and Jiangong Cheng
Chemical Communications 2013 - vol. 49(Issue 96) pp:NaN11268-11268
Publication Date(Web):2013/10/10
DOI:10.1039/C3CC46571C
A new reaction based fluorescence turn-off strategy for detection of secondary amines was developed. The probe shows fast response and high selectivity to secondary amines in solution/film at sub-ppm levels through chromogenic and fluorescent dual-mode signal changes.
Co-reporter:Chao He, Qingguo He, Changmin Deng, Liqi Shi, Defeng Zhu, Yanyan Fu, Huimin Cao and Jiangong Cheng
Chemical Communications 2010 - vol. 46(Issue 40) pp:NaN7538-7538
Publication Date(Web):2010/09/15
DOI:10.1039/C0CC01972K
A sensitive, selective, reversible, and easy performance way of detecting electron donating volatile amines such as abused drug methamphetamine (MAPA) has been developed.
Co-reporter:Yixun Gao, Wei Xu, Defeng Zhu, Lei Chen, Yanyan Fu, Qingguo He, Huimin Cao and Jiangong Cheng
Journal of Materials Chemistry A 2015 - vol. 3(Issue 9) pp:NaN4826-4826
Publication Date(Web):2014/11/26
DOI:10.1039/C4TA05704J
Compared with nitroaromatic explosive detection, nitrate ester explosive detection has not received considerable attention possibly due to the absence of an aromatic ring and their difficulty in being detected. An eight triphenylamino-pyrenyl substituted POSS (P8PT) was designed as a sensory material. POSS was chosen as the skeleton due to its nano structure, multiple reactive sites, structural similarity with nitrate esters and high thermal stability, which will contribute to large surface area induced high sensitivity, tunable sensory units number, stronger interaction force with nitrate esters and high stability. For comparison, triphenylamino-pyrene (Py-TPA) (without POSS), one and three Py-TPA substituted POSS were also synthesized and characterized. Their chemical structures, photophysical and electrochemical properties show that P8PT has a 3-D symmetrical spatial conformation, higher molar extinction coefficient, higher area-to-volume ratio, multiple exciton transfer path, and matched energy level with nitrate ester explosives, which will all contribute to highly efficient sensing performance and efficient selectivity for the detection of nitrate ester explosives such as nitroglycerin (NG). The fluorescence of the P8PT film is 63% quenched upon exposure to a saturated vapor of NG for 50 s and 92% quenched for 300 s at room temperature due to photoinduced electron transfer between the probe and NG. These results reveal that P8PT is suitable for preparing a highly sensitive and efficient thin-film device for detecting nitrate esters.
Co-reporter:Liqi Shi, Chao He, Defeng Zhu, Qingguo He, Yang Li, Yan Chen, Yuxi Sun, Yanyan Fu, Dan Wen, Huimin Cao and Jiangong Cheng
Journal of Materials Chemistry A 2012 - vol. 22(Issue 23) pp:NaN11635-11635
Publication Date(Web):2012/04/05
DOI:10.1039/C2JM30933E
A series of benzothiadiazole-pyridine branched triphenylamine derivatives TPA1BP, TPA2BP and TPA3BP have been designed and synthesized to sense aniline vapor with distinguished sensitivity, selectivity and repeatability via photoinduced electron transfer (PET). Suitable energy levels ensure the high selectivity to aniline for all three sensory materials. However, the aggregations of the three materials in the film state on a quartz substrate increase along with the branches, which highly deteriorate the sensing performance for less efficient fluorescence, lower contact area and inferior vapor penetration. The oriented ZnO nanorod array is introduced as the substrate to eliminate the aggregation and enhance the sensing performance, because of its high surface-to-volume ratio and 3D structure. Therefore, the cooperative effect that the sensing performance of TPAnBP increases with the number of branches could be observed; fluorescence intensities of the films on the nano-substrate are 34%, 45% and 54% quenched for TPA1BP, TPA2BP and TPA3BP, respectively, after exposure to 300 ppm aniline vapor for less than 5 s. Moreover, the fluorescences of all three sensory materials are almost 100% recovered by eluting with fresh air for 20 s and could be reused immediately. The detection limits are predicted to be 1 ppm for TPA1BP, 100 ppb for TPA2BP and 1 ppb for TPA3BP according to the fitted plot, demonstrating a significant cooperative effect of the molecular branches.
Co-reporter:Chang He, Qingguo He, Yuanping Yi, Guanglong Wu, Fenglian Bai, Zhigang Shuai and Yongfang Li
Journal of Materials Chemistry A 2008 - vol. 18(Issue 34) pp:NaN4090-4090
Publication Date(Web):2008/07/21
DOI:10.1039/B807456A
A new solution processable star-shaped organic molecule S(TPA-BT) has been synthesized for application in organic solar cells (OSCs). The properties and structures of S(TPA-BT) and a related linear molecule L(TPA-BT) were studied, including UV-visible spectroscopy, hole charge mobility, and theoretical calculated geometry and electronic properties. S(TPA-BT) film shows a broader and stronger absorption band in the range of 440–670 nm, lower band gap of 1.86 eV, higher hole mobility of 4.71 × 10−5 cm2V−1 s−1 and better film-forming properties compared with those of L(TPA-BT) film. ITO/PEDOT:PSS/S(TPA-BT) or L(TPA-BT):PCBM/Ba/Al bulk-heterojunction OSCs were fabricated with S(TPA-BT) or L(TPA-BT) as donor material. The power conversion efficiency (PCE) of an OSC based on a blend of S(TPA-BT) and PCBM (1 : 3, w/w) reached 1.33% under A.M. 1.5 illumination, 100 mW cm−2, with a short-circuit current density (JSC) of 4.18 mA cm−2, an open circuit voltage of 0.81 V, and a fill factor of 39%. The PCE of 1.33% and Jsc of 4.18 mA cm−2 are among the highest values reported so far for solution processable OSCs.
toluidine
Ammonium, monohydrate
Acid Thickener
Formamide, N,N-dimethyl-
Benzenamine, 4-[6-[2-(3,5,7,9,11,13,15-heptaethenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)ethenyl]-1-pyrenyl]-N,N-diphenyl-
POLY[(PHENYLIMINO)-1,4-PHENYLENE(9,9-DIOCTYL-9H-FLUORENE-2,7-DIYL)-1,4-PHENYLENE]
2-Bromo-6-tert-butylpyridine
5-bromo-2-hydroxybenzene-1,3-dicarbaldehyde
2-Hydroxybenzene-1,3,5-tricarbaldehyde