Co-reporter:Yanni Chen, Lingling Guo, Liqiang Liu, Shanshan Song, Hua Kuang, and Chuanlai Xu
Journal of Agricultural and Food Chemistry September 20, 2017 Volume 65(Issue 37) pp:8248-8248
Publication Date(Web):August 27, 2017
DOI:10.1021/acs.jafc.7b03190
Group-specific monoclonal antibodies (Mabs) with selectivity for 27 sulfonamides were developed based on new combinations of immunogen and coating antigen. The Mab was able to recognize 27 sulfonamides with 50% inhibition concentration (IC50) values ranging from 0.15 to 15.38 μg/L. In particular, the IC50 values for five sulfonamides (sulfamethazine, sulfaquinoxaline, sulfamonomethoxine, sulfadimethoxine, and sulfamethoxazole) were 0.51, 0.15, 0.56, 0.54, and 2.14 μg/L, respectively. On the basis of the Mab, an immunochromatographic lateral flow strip test was established for rapid screening of sulfonamides in honey samples. The visual limit of detection of the strip test for most sulfonamides in spiked honey samples was below 10 μg/kg, satisfying the requirements of authorities. Positive honey and pork liver samples, which had been confirmed by high-performance liquid chromatography/mass spectrometry, were used to validate the reliability of the proposed strip test. The immunochromatographic lateral flow strip test provides a rapid and convenient method for fast screening of sulfonamides in honey samples.Keywords: honey samples; immunochromatographic lateral flow strip test; monoclonal antibody; pork liver samples; sulfonamides;
Co-reporter:Wei Ma, Liguang Xu, André F. de Moura, Xiaoling Wu, Hua Kuang, Chuanlai Xu, and Nicholas A. Kotov
Chemical Reviews June 28, 2017 Volume 117(Issue 12) pp:8041-8041
Publication Date(Web):April 20, 2017
DOI:10.1021/acs.chemrev.6b00755
The field of chiral inorganic nanostructures is rapidly expanding. It started from the observation of strong circular dichroism during the synthesis of individual nanoparticles (NPs) and their assemblies and expanded to sophisticated synthetic protocols involving nanostructures from metals, semiconductors, ceramics, and nanocarbons. Besides the well-established chirality transfer from bioorganic molecules, other methods to impart handedness to nanoscale matter specific to inorganic materials were discovered, including three-dimentional lithography, multiphoton chirality transfer, polarization effects in nanoscale assemblies, and others. Multiple chiral geometries were observed with characteristic scales from ångströms to microns. Uniquely high values of chiral anisotropy factors that spurred the development of the field and differentiate it from chiral structures studied before, are now well understood; they originate from strong resonances of incident electromagnetic waves with plasmonic and excitonic states typical for metals and semiconductors. At the same time, distinct similarities with chiral supramolecular and biological systems also emerged. They can be seen in the synthesis and separation methods, chemical properties of individual NPs, geometries of the nanoparticle assemblies, and interactions with biological membranes. Their analysis can help us understand in greater depth the role of chiral asymmetry in nature inclusive of both earth and space. Consideration of both differences and similarities between chiral inorganic, organic, and biological nanostructures will also accelerate the development of technologies based on chiroplasmonic and chiroexcitonic effects. This review will cover both experiment and theory of chiral nanostructures starting with the origin and multiple components of mirror asymmetry of individual NPs and their assemblies. We shall consider four different types of chirality in nanostructures and related physical, chemical, and biological effects. Synthetic methods for chiral inorganic nanostructures are systematized according to chirality types, materials, and scales. We also assess technological prospects of chiral inorganic materials with current front runners being biosensing, chiral catalysis, and chiral photonics. Prospective venues for future fundamental research are discussed in the conclusion of this review.
Co-reporter:Wei Ma, Pan Fu, Maozhong Sun, Liguang Xu, Hua Kuang, and Chuanlai Xu
Journal of the American Chemical Society August 30, 2017 Volume 139(Issue 34) pp:11752-11752
Publication Date(Web):August 1, 2017
DOI:10.1021/jacs.7b03617
The development of a unique and universal strategy for the simultaneous quantification of different types of biomolecules (i.e., nucleic acids and proteins) in living cells is extremely challenging. Herein, a two-signal platform, based upon surface-enhanced Raman scattering and upconversion, for the ultrasensitive and quantitative in situ detection of microRNA (miR)-21 and telomerase in living cells is reported. In the presence of miR-21 and telomerase, the hybridization of miR-21 with a molecular beacon leads to the separation of 3,3′-diethylthiocarbamyl cyanine iodide-modified Au NR dimers, resulting in a decrease in Raman signal. Also, the target telomerase triggers elongation of the telomerase primer strands, followed by substitutional hybridization and release of upconversion nanoparticles, leading to an increase in luminescence. A linear relationship between the Raman intensities and logarithmic concentration of intracellular miR-21 between 0.021 and 22.36 amol/ngRNA is observed, and the limit of detection (LOD) was determined to be 0.011 amol/ngRNA. The luminescence data show a linear response between 0.6 × 10–12 and 31 × 10–12 IU for logarithmic concentration of intracellular telomerase with a LOD of 3.2 × 10–13 IU. These results are in good agreement with Raman and confocal imaging. Importantly, the ultrasensitive detection of miR-21 was possible due to strong plasmonic “hot spots”. This innovative two-signal approach can be utilized for the quantitative and precise detection of many types of signaling molecules in living cells and to understand the chemistry within cellular systems and its application in the diagnosis of disease.
Co-reporter:Yanni Chen;Liqiang Liu;Liguang Xu;Shanshan Song;Gang Cui
Nano Research 2017 Volume 10( Issue 8) pp:2833-2844
Publication Date(Web):03 April 2017
DOI:10.1007/s12274-017-1490-x
A gold immunochromatographic sensor (GICS) was developed for the rapid detection of 26 sulfonamides in honey samples. The sensor was based on a group-specific monoclonal antibody (mAb) that can recognize all 26 sulfonamides. Three haptens (hapten 1 with a thiazole ring, hapten 2 with a benzene ring, and hapten 3 with a straight carbon chain) were used for antigen preparation. With hybridoma technology, a group-specific mAb was screened with a 50% maximal inhibitory concentration (IC50) against sulfathizole (STZ) and the other 25 analogues ranging from 0.08 to 90.18 ng/mL. Mono-dispersed gold nanoparticles were conjugated with the mAb to develop the lateral immunochromatographic strip. A labeled antibody concentration of 0.1 μg/mL and a coating antigen concentration of 0.2 μg/mL in the test line were chosen for strip preparation. Under optimized conditions, the visual limits of detection (vLOD) for the concentrations of STZ, sulfamethoxazole, sulfamethizole, sulfadiazine, sulfamerazine, sulfadimethoxine, sulfamonomethoxine, sulfameter, sulfamethoxypyridazine, and sulfachloropyridazine were 5, 0.25, 0.25, 10, 5, 10, 25, 2.5, 5, 0.25, and 10 μg/kg, respectively. Scanner analysis in honey samples revealed good performance for detection of the 26 sulfonamides. Commercial honey samples were tested with the sensor and positive results were confirmed with high-performance liquid chromatography. The proposed strip sensor provides a convenient method for the rapid and reliable determination of sulfonamides pollutants in honey samples.
Co-reporter:Fengli Gao;Liqiang Liu;Gang Cui;Liguang Xu;Xiaoling Wu;Chuanlai Xu
Nanoscale (2009-Present) 2017 vol. 9(Issue 1) pp:223-229
Publication Date(Web):2016/12/22
DOI:10.1039/C6NR08264E
Reliable and ultrasensitive quantification of dopamine (DA) is essential in the precise diagnotherapy of neurological diseases. In this study, dual mode counterpropagating-responsive gold@silver nanoparticle–gold nanorod (Au@AgNP–AuNR) nano-assemblies were fabricated for the precise quantification of DA. The plasmonic Au@AgNP–AuNR assemblies possessed high surface-enhanced Raman scattering (SERS) activity and strong fluorescence quenching, due to the prominent electromagnetic enhancement between the hotspots of the assemblies. In the presence of a DA target, the Au@AgNP–AuNR assemblies dissociated, leading to an increase in fluorescence intensity and a decrease in SERS intensity. The limit of detection (LOD) of DA was 0.04 fM and 0.02 fM by the fluorescence method and SERS method, respectively. The linear range was 0.1–10 fM. These findings demonstrated that the simultaneous positive fluorescence response and negative SERS response ensured the accurate detection of DA, which opens up a new avenue for the early diagnotherapy of neurological diseases.
Co-reporter:Juan Peng;Liqiang Liu;Liguang Xu;Shanshan Song;Gang Cui
Nano Research 2017 Volume 10( Issue 1) pp:108-120
Publication Date(Web):2017 January
DOI:10.1007/s12274-016-1270-z
For rapid and simultaneous detection of (fluoro)quinolones, a broadly specific monoclonal antibody (mAb) that recognizes 32 (fluoro)quinolone antibiotics was prepared using a mixture of a norfloxacin derivative and a sarfloxacin derivative as the hapten. An immunochromatographic strip based on gold nanoparticles (AuNPs) was then assembled with goat anti-mouse antibody and antigen (sarfloxacin coupled to ovalbumin), used to form the C line and T line, respectively. This antigen competes with the (fluoro)quinolones in a sample incubated with mAbs labeled with AuNPs. The strip can detect 32 (fluoro)quinolones including oxolinic acid, nalidixic acid, miloxacin, pipemidic acid, piromidic acid, rosoxacin, cinoxacin, norfloxacin, pefloxacin, lomfloxacin, enofloxacin, fleroxacin, ciprofloxacin, enrofloxacin, dafloxacin, orbifloxacin, sparfloxacin, gemifloxacin, besifloxacin, balofloxacin, gatifloxacin, moxifloxacin, nadifloxacin, ofloxacin, marbofloxacin, flumequine, pazufloxacin, prulifloxacin, sarafloxacin, difloxacin, trovafloxacin, and tosufloxacin in milk within 10 min with the naked eye. The cut-off values of the strip range from 1 to 100 ng/mL and the limits of detection are 0.1–10 ng/mL. The strip does not cross-react with antibiotics including tetracycline, sulfamethazine, ampicillin, erythromycin, aflatoxin B1, or gentamicin. In short, this immunochromatographic strip is a very useful tool for the primary screening of (fluoro)quinolones in milk.
Co-reporter:Wenbin Wang;Liqiang Liu;Shanshan Song;Liguang Xu
Microchimica Acta 2017 Volume 184( Issue 3) pp:715-724
Publication Date(Web):2017 March
DOI:10.1007/s00604-016-2028-8
A lateral flow assay for rapid, simple and efficient determination of L. monocytogenes is presented. A monoclonal antibody (mAb) 1C1 against the peptide from P60 protein of L. monocytogenes was prepared and labeled with gold nanoparticles (AuNPs). The mAb 1C1 was paired with the mAb 10E7 against the P60 protein of all the Listeria spp. and used as a capture bioligand in a lateral flow assay. The AuNP-based strip test can detect the supernatant of eight common L. monocytogenes serotypes including 1/2a, 1/2b, and 4b with an equivalent detection limit of 3.7 × 106 CFU⋅mL−1 but does not detect four other Listeria spp. (L. ivanovii, L. innocua, L. welshimeri, and L. grayi). There was no cross-reactivity with six other Gram-negative and Gram-positive bacteria. The method was applied to the quantification of L. monocytogenes species in spiked milk samples within 13 h.
Co-reporter:Aihua Qu;Xiaoling Wu;Liguang Xu;Liqiang Liu;Wei Ma;Chuanlai Xu
Nanoscale (2009-Present) 2017 vol. 9(Issue 11) pp:3865-3872
Publication Date(Web):2017/03/17
DOI:10.1039/C6NR09114H
Alpha-fetoprotein (AFP) and mucoprotein1 (mucin-1) are two important disease biomarkers. Self-assembled gold nanoparticles (AuNPs) and upconversion nanoparticle (Au–Au–UCNP) trimers based on aptamers were developed for the ultrasensitive detection of AFP and mucin-1. The Au–Au–UCNP trimers produced ideal optical signals, with prominent Raman enhancement and fluorescence quenching effects. The surface-enhanced Raman scattering (SERS) intensity decreased in the presence of mucin-1 and the luminescence intensity increased in the presence of AFP. A limit of detection (LOD) of 4.1 aM and a wide linear range of 0.01–10 fM for the detection of mucin-1 were obtained with this SERS-encoded sensing system. Using the luminescence-encoded sensing system, a LOD of 0.059 aM and a wide linear range of 1–100 aM for the detection of AFP were obtained. These LODs are the lowest values reported so far. This approach has the advantage of detecting two disease biomarkers simultaneously.
Co-reporter:Aihua Qu;Xiaoling Wu;Liguang Xu;Liqiang Liu;Wei Ma;Chuanlai Xu
Nanoscale (2009-Present) 2017 vol. 9(Issue 11) pp:3865-3872
Publication Date(Web):2017/03/17
DOI:10.1039/C6NR09114H
Alpha-fetoprotein (AFP) and mucoprotein1 (mucin-1) are two important disease biomarkers. Self-assembled gold nanoparticles (AuNPs) and upconversion nanoparticle (Au–Au–UCNP) trimers based on aptamers were developed for the ultrasensitive detection of AFP and mucin-1. The Au–Au–UCNP trimers produced ideal optical signals, with prominent Raman enhancement and fluorescence quenching effects. The surface-enhanced Raman scattering (SERS) intensity decreased in the presence of mucin-1 and the luminescence intensity increased in the presence of AFP. A limit of detection (LOD) of 4.1 aM and a wide linear range of 0.01–10 fM for the detection of mucin-1 were obtained with this SERS-encoded sensing system. Using the luminescence-encoded sensing system, a LOD of 0.059 aM and a wide linear range of 1–100 aM for the detection of AFP were obtained. These LODs are the lowest values reported so far. This approach has the advantage of detecting two disease biomarkers simultaneously.
Co-reporter:Si Li;Liguang Xu;Maozhong Sun;Xiaoling Wu;Liqiang Liu;Chuanlai Xu
Advanced Materials 2017 Volume 29(Issue 19) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201606086
This study strategically fabricates multifunctional nanopyramids to allow the ultrasensitive quantification of dual microRNAs (miR-203b and miR-21) in living cells and their responsive bioimaging in vivo. The nanopyramids, composed of Au-Cu9S5 nanoparticles (NPs), upconversion NPs (UCNPs), and Ag2S NPs, emit two luminescent signals simultaneously with excitation at 808 nm, arising from the UCNPs at 541 nm in the visible region and from the Ag2S NPs at 1227 nm in the second window of near-infrared (NIR-II) region. The upconversion luminescence has a linear relationship with miR-203b from 0.13 to 54.54 fmol per 10 µgRNA and a limit of detection (LOD) of 0.09 fmol per 10 µgRNA, whereas the Ag2S NP luminescence has a linear relationship with miR-21 from 0.37 to 43.56 fmol per 10 µgRNA, with a LOD of 0.23 fmol per 10 µgRNA. Significantly, this study demonstrates that the nanopyramids can be successfully used for miRs-responsive bioimaging in a tumor-bearing animal model. Furthermore, taking advantage of the photothermal capabilities of pyramids, the tumors can also be eliminated completely. These nanopyramids not only overcome the obstacles in the simultaneous detection of multiple miRs at the cellular level but also provide a cancer theranostic platform in vivo.
Co-reporter:Fengli Gao;Maozhong Sun;Wei Ma;Xiaoling Wu;Liqiang Liu;Chuanlai Xu
Advanced Materials 2017 Volume 29(Issue 18) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201606864
Photodynamic therapy (PDT) agent, which generates singlet oxygen (1O2) under light, has attracted significant attention for its broad biological and medical applications. Here, DNA-driven shell–satellite (SS) gold assemblies as chiral photosensitizers are first fabricated. The chiral plasmonic nanostructure, coupling with cysteine enantiomers on its surface, exhibits intense chiroplasmonic activities (−40.2 ± 2.6 mdeg) in the visible region. These chiral SS nanoassemblies have high reactive oxygen species generating efficiency under circular polarized light illumination, resulting in a 1O2 quantum yield of 1.09. Meanwhile, it is found that SS could be utilized as PDT agent with remarkable efficiency under right circular polarized light irradiation in vitro and in vivo, allowing X-ray computed tomography (CT) and photoacoustics (PA) imaging for tumors simultaneously. The achievements reveal that the enantiomer-dependent and structure-induced nanoassemblies play an important role in PDT effects. The present researches open up a new avenue for cancer diagnose and therapy using chiral nanostructures as multifunctional platform.
Co-reporter:Wei Ma;Maozhong Sun;Pan Fu;Si Li;Liguang Xu;Chuanlai Xu
Advanced Materials 2017 Volume 29(Issue 42) pp:
Publication Date(Web):2017/11/01
DOI:10.1002/adma.201703410
AbstractAssemblies of nanomaterials for biological applications in living cells have attracted much attention. Herein, graphene oxide (GO)–gold nanoparticle (Au NP) assemblies are driven by a splint DNA strand, which is designed with two regions at both ends that are complementary with the DNA sequence anchored on the surface of the GO and the Au NPs. In the presence of microRNA (miR)-21 and epithelial cell-adhesion molecule (EpCAM), the hybridization of miR-21 with a molecular probe leads to the separation of 6-fluorescein-phosphoramidite-modified Au NPs from GO, resulting in a decrease in the Raman signal, while EpCAM recognition reduces circular dichroism (CD) signals. The CD signals reverse from negative in original assemblies into positive when reacted with cells, which correlates with two enantiomer geometries. The EpCAM detection has a good linear range of 8.47–74.78 pg mL−1 and a limit of detection (LOD) of 3.63 pg mL−1, whereas miR-21 detection displays an outstanding linear range of 0.07–13.68 amol ng−1RNA and LOD of 0.03 amol ng−1RNA. All the results are in good agreement with those of the Raman and confocal bioimaging. The strategy opens up an avenue to allow the highly accurate and reliable diagnosis (dual targets) of clinic diseases.
Co-reporter:Aihua Qu;Liguang Xu;Maozhong Sun;Liqiang Liu;Chuanlai Xu
Advanced Functional Materials 2017 Volume 27(Issue 46) pp:
Publication Date(Web):2017/12/01
DOI:10.1002/adfm.201703408
AbstractThe quantitative detection of microRNA (miR) and multimode-imaging-induced photothermal therapy in vivo have become the focus of much attention. Platinum (Pt) decorated gold nanorods (AuNR-Pt) and Ag2S core–satellite (AuNR-Pt@Ag2S) multifunctional nanostructures are fabricated to quantify intracellular miRs (miR-21), near-infrared fluorescence cell quantitative imaging, and tumor ablation in vivo. When combined with miR-21, the nanoassembly displays significant fluorescence intensity in the second window of the near-infrared region (1000–1700 nm) after 808 nm excitation. The Ag2S fluorescence intensity has a good linear relationship with the amount of intracellular miR in the range of 0.054–20.45 amol ngRNA −1 and a limit of detection of 0.0082 amol ngRNA −1. The nanoassembly is also used to develop multimodal bioimaging, including near-infrared, X-ray computed tomographic, and photoacoustic imaging in HeLa-tumor-bearing mice. Moreover, the tumors are completely eliminated by the high photothermal capacity of the AuNR-Pt@Ag2S assembly. This nanoassembly provides a multifunctional nanoplatform for the ultrasensitive detection of miRs and tumor diagnosis and therapy in vivo.
Co-reporter:Xiaoling Wu;Liguang Xu;Wei Ma;Liqiang Liu;Nicholas A. Kotov;Chuanlai Xu
Advanced Materials 2016 Volume 28( Issue 28) pp:5907-5915
Publication Date(Web):
DOI:10.1002/adma.201601261
Co-reporter:Maozhong Sun;Liguang Xu;Wei Ma;Xiaoling Wu;Libing Wang ;Chuanlai Xu
Advanced Materials 2016 Volume 28( Issue 5) pp:898-904
Publication Date(Web):
DOI:10.1002/adma.201505023
Co-reporter:Liguang Xu;Sen Zhao;Wei Ma;Xiaoling Wu;Si Li;Libing Wang ;Chuanlai Xu
Advanced Functional Materials 2016 Volume 26( Issue 10) pp:1602-1608
Publication Date(Web):
DOI:10.1002/adfm.201504587
The highly sensitive and quantitative biodetection of intracellular telomerase is challenging. A DNA-driven nanoparticle self-assembling pyramid encoding a Raman reporter (Cy5) is reported that detects telomerase in live cells. In the presence of the target, the telomerase primer is extended and the inner DNA chain is replaced, leading to the reduction in the surface-enhanced Raman scattering (SERS) signal and the simultaneous recovery of the fluorescent signal. The SERS signal has a linear range for the detection of telomerase in situ of 1 × 10–14 to 5 × 10–11 IU, with a limit of detection of 6.2 × 10–15 IU. The fluorescent signal is used to confirm the intracellular telomerase activity, demonstrating the efficacy of the designed pyramid probe. This biosensing strategy provides a reliable and ultrasensitive protocol for the quantification of biomarkers in living cells.
Co-reporter:Pan Fu, Maozhong Sun, Liguang Xu, Xiaoling Wu, Liqiang Liu, Hua Kuang, Shanshan Song and Chuanlai Xu
Nanoscale 2016 vol. 8(Issue 32) pp:15008-15015
Publication Date(Web):18 Jul 2016
DOI:10.1039/C6NR04086A
Circular dichroism (CD) has allowed the construction of various chiral nanomaterials for different applications, including biosensing. However, the determination of a simple target-specific, economical, and biocompatible platform using CD with intracellular detection and in situ molecular probing is still required. Here, we show that a DNA zip-fastener structure self-assembled chiral-aptasensor based on gold nanoparticle heterodimers provided an outstanding capability to quantify adenosine-5′-triphosphate (ATP) by addition. The conjugation of two ATP molecules to an adenosine aptamer allowed the formation of a stable ring structure, which formed an ATP-ring adhesive scaffold upon interaction with DNA complementary sequences linked with large gold nanoparticles, the latter were able to drop and result in a decrease in CD signal. We also showed that these low-cytotoxicity and polyethylene glycol (PEG)-steady nanoconjugates were also a one-step incubation technique for the quantification and monitoring of ATP in living cells modified by cell penetrating peptides (TAT) or Cy5. The results showed that the linear intracellular detection range was from 1.5 to 4.2 mM with a limit of detection (LOD) of 0.2 mM. Our findings suggest that this chiroplasmonic sensor is a promising approach for investigating biogenic biomolecules inside cells and living organisms and for assessing their biological activity.
Co-reporter:Wenbin Wang 王文彬;Liqiang Liu 刘丽强;Shanshan Song 宋珊珊
Science China Materials 2016 Volume 59( Issue 8) pp:665-674
Publication Date(Web):2016 August
DOI:10.1007/s40843-016-5077-0
In this study, an innovative competitive immunochromatographic strip sensor was developed for rapid detection of Salmonella based on a genus-specific antilipopolysaccharide (LPS) monoclonal antibody (mAb) and the heterogeneous coating antigen of a LPS-bovine serum albumin conjugate. Gold nanoparticles labeled anti-LPS mAb specifically reacted with the conserved outer core of the Salmonella LPS in the sample and the color formed on the T line was negatively correlated with the number of Salmonella cells. The sensitivity of Ra mutant LPS (without O-specific chains but has the conserved outer core) was 25 ng mL–1, which explained the detection of Salmonella at the genus level. Based on the gray values on the test line, the limit of detection of Salmonella was 103 colony-forming unit (CFU) for all twelve typical strains of Salmonella. The analysis of common Gram-negative and Gram-positive bacteria demonstrated that the strip assay was specific to Salmonella. A milk sample test showed that Salmonella at a low level (1–5 CFU mL–1) was detected without complex biochemical confirmation steps, sophisticated instruments and professional training.沙门氏菌属是全球关注的重要食源性致病菌之一. 本文以沙门氏菌属特异性脂多糖抗体与胶体金纳米粒子进行偶联, 并进行固相化, 装配了适合于快速、可视化分析的金标试纸传感器. 裸眼观察下, 金标试纸条可以识别浓度低至25 ng mL−1的沙门氏菌属脂多糖. 结合灰 度扫描分析, 金标试纸对受试的12种沙门氏菌的敏感性可达到103 菌落形成单位(CFU). 对牛奶样品进行12 h的富集孵育, 该金标试纸条对 沙门氏菌的检测灵敏度可达1个CFU. 金标试纸传感器无需复杂的前处理过程和专业设备, 操作简单, 有效地提高了致病菌的检测效率.
Co-reporter:Liguang Xu;Wenjing Yan;Wei Ma;Xiaoling Wu;Liqaing Liu;Yuan Zhao;Libing Wang;Chuanlai Xu
Advanced Materials 2015 Volume 27( Issue 10) pp:1706-1711
Publication Date(Web):
DOI:10.1002/adma.201402244
Co-reporter:Si Li; Liguang Xu; Wei Ma; Xiaoling Wu; Maozhong Sun; Hua Kuang; Libing Wang; Nicholas A. Kotov;Chuanlai Xu
Journal of the American Chemical Society 2015 Volume 138(Issue 1) pp:306-312
Publication Date(Web):December 21, 2015
DOI:10.1021/jacs.5b10309
Chiral self-assembled nanomaterials with biological applications have attracted great interest. In this study, DNA-driven gold-upconversion nanoparticle (Au-UCNP) pyramids were fabricated to detect intracellular microRNA (miRNA) in real time. The Au-UCNP pyramids are doubly optically active, displaying strong plasmonic circular dichroism (CD) at 521 nm and significant luminescence in 500–600 nm, and therefore can be monitored by both of them. CD will decrease while the luminescence intensity increases in the presence of miRNA. The experimental results show that the CD intensity had an outstanding linear range from 0.073 to 43.65 fmol/10 μgRNA and a limit of detection (LOD) of 0.03 fmol/10 μgRNA, whereas the luminescence intensity ranged from 0.16 to 43.65 fmol/10 μgRNA with a LOD of 0.12 fmol/10 μgRNA. These data indicate that the CD signal is much more sensitive to the concentration of miRNA than the luminescent signal, which is attributed to the strong CD intensity arising from the spin angular momentum of the photon interaction with chiral nanostructures and the plasmonic enhancement of the intrinsic chirality of DNA molecules in the pyramids. This approach opens up a new avenue to the ultrasensitive detection and quantification of miRNA in living cells.
Co-reporter:Changlong Hao;Liguang Xu;Wei Ma;Xiaoling Wu;Libing Wang;Chuanlai Xu
Advanced Functional Materials 2015 Volume 25( Issue 36) pp:5816-5822
Publication Date(Web):
DOI:10.1002/adfm.201502429
Gold-gap-silver nanostructures (GGS NSs) with interior nanobridged gaps are enantioselectively fabricated. Guided by l/d-cysteine, the GGS-L/D (L/D represents l/d-cysteine) NSs show reversed plasmon-induced circular dichroism (CD) signals in the visible region. It is found that the nanogap plays a key role in the plasmonic CD of GGS NSs and the chiroptical response can be tailored by adjusting the amount of cysteine. The anisotropy factor of GGS-L/D NSs with a 0.5 nm interior gap at 430 nm is as high as ≈0.01. The circularly polarized photocatalytic activity of GGS NSs is examined. It is shown that upon irradiation with left-circularly polarized light, the catalytic efficiency of GGS-L NSs is 73-fold and 17-fold higher than that of Au nanoparticles (NPs) and Au@Ag core–shell NPs, respectively. Upon irradiation with right-circularly polarized light, the catalytic activity of GGS-D NSs is about 71 times and 17 times higher than that of Au NPs and Au@Ag core–shell NPs, respectively. These unique chiral NSs with high plasmonic response can be applied to enantioselective catalysis.
Co-reporter:Xiaoling Wu;Liguang Xu;Wei Ma;Liqiang Liu;Wenjing Yan;Libing Wang ;Chuanlai Xu
Advanced Functional Materials 2015 Volume 25( Issue 6) pp:850-854
Publication Date(Web):
DOI:10.1002/adfm.201403161
The strong plasmonic chiroptical activities of gold core-DNA-silver shell nanoparticles (NPs) are reported for the first time, using cytosine-rich single-stranded DNA as the template for the guidance of silver shell growth. The anisotropy factor of the optically active NPs at 420 nm reaches 1.93 × 10−2. Their chiroptical properties are likely induced by the DNA–plasmon interaction and markedly amplified by the strong electromagnetic coupling between the gold core and silver shell.
Co-reporter:Xiaoling Wu, Fengli Gao, Liguang Xu, Hua Kuang, Libing Wang and Chuanlai Xu
RSC Advances 2015 vol. 5(Issue 118) pp:97898-97902
Publication Date(Web):09 Nov 2015
DOI:10.1039/C5RA19628K
The accurate monitoring of trace cancer biomarkers is crucial for the early diagnosis of cancer. In the present study, we constructed a gold nanorod–quantum dot core–satellite assembly using a PSA-aptamer and its complementary DNA and developed an ultrasensitive fluorescence-aptasensor for the detection of prostate specific antigen (PSA) by monitoring fluorescence intensity. The limit of detection (LOD) for PSA was 0.029 aM, with an excellent linear range from 0.1 aM to 10 aM. This super-sensitive aptasensor was demonstrated to be robust in the analysis of human serum samples, and shows great potential for early cancer diagnosis and therapy.
Co-reporter:Liguang Xu, Honghong Yin, Wei Ma, Hua Kuang, Libing Wang, Chuanlai Xu
Biosensors and Bioelectronics 2015 Volume 67() pp:472-476
Publication Date(Web):15 May 2015
DOI:10.1016/j.bios.2014.08.088
•An ultrasensitive method for SERS detection of Hg2+ was developed based on the gold nanoparticles chain induced by T–Hg2+–T base pairs.•This method could achieve a low limit of detection (LOD) of 0.45 pg mL−1 in the range of 0.001–0.5 ng mL−1.•The practicability of the developed method was favorable in the analysis of real samples.Mercuric ions (Hg2+) mediate the transformation of single-stranded DNA to form double helical DNA by T–Hg2+–T interaction between base pairs. With this strategy, DNA modified gold nanoparticles (Au NPs) were assembled into chains which were displayed remarkable surface-enhanced Raman scattering (SERS) signal. Under optimized conditions, the length of gold nanochains was directly proportional to the mercuric ions concentrations over 0.001–0.5 ng mL−1 and the limit of detection (LOD) in drinking water was as low as 0.45 pg mL−1. With ultrasensitivity and excellent selectivity, this feasible and simple method is potentially as a promising tool for monitoring of mercury ions in food safety and environmental applications.
Co-reporter:Changrui Xing, Liqiang Liu, Shanshan Song, Min Feng, Hua Kuang, Chuanlai Xu
Biosensors and Bioelectronics 2015 Volume 66() pp:445-453
Publication Date(Web):15 April 2015
DOI:10.1016/j.bios.2014.12.004
•A multicomponent lateral-flow assay based on an antibody–antigen reaction for the rapid and simultaneous detection of five trace contaminants was developed.•The cut-off values for the strip test were 4 ng/mL for Pb(II), 1 ng/mL for MC–LR, 0.1 ng/mL for CAP, 5 ng/mL for T, and 5 ng/mL for CTN.•The assay was evaluated using spiked water samples, and the accuracy and reproducibility of the results were good.In this paper, we describe the development of a multicomponent lateral-flow assay based on an antibody–antigen reaction for the rapid and simultaneous detection of trace contaminants in water, including a heavy metal, algal toxin, antibiotic, hormone, and pesticide. The representative analytes chosen for the study were lead (Pb(II), microcystin–leucine–arginine (MC–LR), chloramphenicol (CAP), testosterone (T), and chlorothalonil (CTN). Five different antigens were immobilized separately in five test lines on a nitrocellulose membrane. The monoclonal antibodies specifically recognized the corresponding antigens, and there was no cross-reactivity between the antibodies in the detection assay. Samples or standards containing the five analytes were preincubated with the freeze-dried colloidal-gold-labeled monoclonal antibody conjugates to improve the sensitivity of the assay. The results were obtained within 20 min with a paper-based sensor. The cut-off values for the strip test were 4 ng/mL for Pb(II), 1 ng/mL for MC–LR, 0.1 ng/mL for CAP, 5 ng/mL for T, and 5 ng/mL for CTN. The assay was evaluated using spiked water samples, and the accuracy and reproducibility of the results were good. In summary, this lateral-flow device provides an effective and rapid method for the onsite detection of multiple contaminants in water samples, with no treatment or devices required.
Co-reporter:Yuan Zhao, Liguang Xu, Wei Ma, Libing Wang, Hua Kuang, Chuanlai Xu, and Nicholas A. Kotov
Nano Letters 2014 Volume 14(Issue 7) pp:3908-3913
Publication Date(Web):May 23, 2014
DOI:10.1021/nl501166m
DNA-bridged pairs of seemingly spherical metallic nanoparticles (NPs) have chiral geometry due to the nonideal oblong shape of the particles and scissor-like conformation. Here we demonstrate that deposition of gold and silver shells around the NP heterodimers enables spectral modulation of their chiroplasmonic bands in 400–600 nm region and results in significantly enhanced optical activity with g-factors reaching 1.21 × 10–2. The multimetal heterodimers optimized for coupling with the spin angular momentum of incident photons enable polymerase chain reaction (PCR)-based DNA detection at the zeptomolar level. This significant improvement in the sensitivity of detection is attributed to improvement of base pairing in the presence of NPs, low background for chiroplasmonic detection protocol, and enhancement of photon–plasmon coupling for light with helicity matching that of the twisted geometry of the heterodimers.
Co-reporter:Maozhong Sun, Wei Ma, Liguang Xu, Libing Wang, Hua Kuang and Chuanlai Xu
Journal of Materials Chemistry A 2014 vol. 2(Issue 15) pp:2702-2706
Publication Date(Web):28 Jan 2014
DOI:10.1039/C4TC00040D
Plasmonic nanoparticle (NP) chiral dimers are fabricated using different types of homogenous materials. However, the effect of semiconductor nanoscale dimers is unknown. This paper describes the chiroptical effect of different plasmonic metal–semiconductor hybrid nanostructures composed of gold (Au), silver (Ag) NPs and quantum dots (QDs). Three types of DNA-mediated high yield dimers were obtained, which had a distinct diverse chiroptical effect of peak position and intensity. The semiconductor QDs dimers showed a weak CD signal at 600 nm, while enhanced signals were observed after coupling with Au or Ag NPs. This interesting chiroptical effect, which originated from the assembled chiral geometry, provides a new route for further chiral structures fabrication and applications.
Co-reporter:Hua Kuang, Honghong Yin, Liqiang Liu, Liguang Xu, Wei Ma, and Chuanlai Xu
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 1) pp:364
Publication Date(Web):November 19, 2013
DOI:10.1021/am4043678
A sensitive plasmonic chirality-based aptasensor for the detection of bisphenol A (BPA) was developed. Asymmetric plasmonic nanoparticle dimers were produced by the hybridization of a BPA aptamer and its complementary sequence modified nanoparticles. Under different concentrations of BPA, the intensity of the chiral signal was varied. A low limit of detection of 0.008 ng/mL was obtained in the range 0.02–5 ng/mL.Keywords: aptasensor; asymmetric; bisphenol A; detection; plasmonic; sensitive;
Co-reporter:Honghong Yin, Hua Kuang, Liqiang Liu, Liguang Xu, Wei Ma, Libing Wang, and Chuanlai Xu
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 7) pp:4752
Publication Date(Web):March 10, 2014
DOI:10.1021/am405482a
A novel biosensor for ultrasensitive detection of copper (Cu2+) was established based on the assembly of magnetic nanoparticles induced by the Cu2+-dependent ligation DNAzyme. With a low limit of detection of 2.8 nM and high specificity, this method has the potential to serve as a general platform for the detection of heavy metal ions.Keywords: copper ions; ligation DNAzyme; MRI sensor;
Co-reporter:Yuan Zhao, Liqiang Liu, Dezhao Kong, Hua Kuang, Libing Wang, and Chuanlai Xu
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 23) pp:21178
Publication Date(Web):November 10, 2014
DOI:10.1021/am506104r
Accurate and highly sensitive detection of Pantoea stewartii sbusp. stewartii-NCPPB 449 (PSS) is urgently required for international shipments due to tremendous agricultural economic losses. Herein, a dual amplified electrochemical sandwich immunosensor for PSS detection was developed, utilizing the good specificity and low cost of electrochemical immunoassay, the favorable conductivity and large specific surface area of gold nanoparticles (Au NPs), and the excellent catalytic ability of and horseradish peroxidase (HRP). A linear curve between current response and PSS concentration was established, and the limit of detection (LOD) was 7.8 × 103 cfu/mL, which is 20 times lower than that for conventional enzyme-linked immunosorbent assay (ELISA). This strategy is a useful approach for the highly sensitive detection of plant pathogenic bacterium.Keywords: Au NPs; electrochemical; immunosensor; PSS; sensitive detection
Co-reporter:Yuan Zhao, Liqiang Liu, Hua Kuang, Libing Wang and Chuanlai Xu
RSC Advances 2014 vol. 4(Issue 99) pp:56052-56056
Publication Date(Web):22 Oct 2014
DOI:10.1039/C4RA11112E
An innovative Raman sensor was developed for DNA detection, based on silver@gold (Ag@Au) core–shell nanoparticle (NP) assemblies fabricated by a polymerase chain reaction (PCR). The combination of exponential amplification by PCR and the amplified Raman signal achieved DNA detection of 11.8 aM.
Co-reporter:Xiaoling Wu ; Liguang Xu ; Liqiang Liu ; Wei Ma ; Honghong Yin ; Hua Kuang ; Libing Wang ; Chuanlai Xu ;Nicholas A. Kotov
Journal of the American Chemical Society 2013 Volume 135(Issue 49) pp:18629-18636
Publication Date(Web):November 18, 2013
DOI:10.1021/ja4095445
Chiral assemblies of nanoparticles (NPs) are typically constructed with helical or tetrahedral geometries. Simple pairs of NPs are not expected to display chirality due to basic symmetry considerations made under the assumption of their spherical geometry. In this study we demonstrate that assemblies consisting of two metallic NPs do possess chirality and strongly rotate polarization of light. Their chiroplasmonic properties are attributed to the prolate geometry of individual colloidal particles. When bridged by biomolecules, the NP pairs acquire scissor-like geometry, with the long axes of NPs forming an angle of ∼9°. This small dihedral angle results in chirality of the NP pair, while the consistency of its sign due to the specific conformation of the bridging biomacromolecules breaks the enantiomeric equivalence of the NP pairs. Strong polarization rotation in these nanoassemblies makes possible their utilization in biological analysis. Heterodimers of gold and silver NPs were made using antibody–antigen bridges. Taking advantage of their chiroplasmonic properties, we investigated their bioanalitical potential for detection of an environmental toxin, microcystin-LR, and a cancer biomarker, prostate-specific antigen. The order-of-magnitude improvements in limits of detection compared to all other analytical techniques are attributed to plasmonic enhancement of intrinsic chirality of biological compounds, strong optical coupling of photons with NP assemblies with twisted geometries, and signal amplification due to the bisignate nature of circular dichroism bands.
Co-reporter:Liguang Xu, Honghong Yin, Wei Ma, Libing Wang, Hua Kuang, and Chuanlai Xu
The Journal of Physical Chemistry B 2013 Volume 117(Issue 46) pp:14367-14371
Publication Date(Web):October 21, 2013
DOI:10.1021/jp4087656
A MRI biosensor for sensitive and specific detection of lead ions (Pb2+) was developed based on DNAzyme-induced cleavage of magnetic nanoparticles (MNPs). A low limit of detection (LOD) of 0.05 ng mL–1 was obtained. This biosensor has the potential to serve as a general platform for the detection of heavy metal ions.
Co-reporter:Maozhong Sun, Wei Ma, Liguang Xu, Libing Wang, Hua Kuang and Chuanlai Xu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 15) pp:NaN2706-2706
Publication Date(Web):2014/01/28
DOI:10.1039/C4TC00040D
Plasmonic nanoparticle (NP) chiral dimers are fabricated using different types of homogenous materials. However, the effect of semiconductor nanoscale dimers is unknown. This paper describes the chiroptical effect of different plasmonic metal–semiconductor hybrid nanostructures composed of gold (Au), silver (Ag) NPs and quantum dots (QDs). Three types of DNA-mediated high yield dimers were obtained, which had a distinct diverse chiroptical effect of peak position and intensity. The semiconductor QDs dimers showed a weak CD signal at 600 nm, while enhanced signals were observed after coupling with Au or Ag NPs. This interesting chiroptical effect, which originated from the assembled chiral geometry, provides a new route for further chiral structures fabrication and applications.
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