Co-reporter:Yu Chen, Lei Chen, Ruilin Bi, Lan Xu, Yan Liu
Analytica Chimica Acta 2012 Volume 754() pp:83-90
Publication Date(Web):19 November 2012
DOI:10.1016/j.aca.2012.09.048
A novel chiral molecularly imprinted polymer (MIP) sensor for l-Phenylalanine has been developed, which is constructed by electrochemically driven cross-linking a pendant polymer precursor, poly[2-(N-carbazolyl)ethyl methacrylate-co-meth-acrylic acid]s (PCEMMAs). In this MIP sensing material, the recognition sites, the insulating polymethylacrylic acid (PMAA), were covalently bonded to the conducting polycarbazole which could be used as signal transfer interface between recognition layer and electrode. The mole ratio of copolymerizing monomers, 2-(N-carbazolyl) ethyl methacrylate:methylacrylic acid (CE:MAA), and the scanning cycles of electropolymerization were adjusted during the preparation of MIP sensing material. The optimized conditions, CE:MAA = 3:2 and 20 scanning cycles, were obtained. And then the properties of MIP films were characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle. Open circuit potential–time technique was used to estimate the enantioselectivity of the MIP sensor. The results indicate that the promising sensor preferentially responses l-Phenylalanine (l-Phe) over d-Phenylalanine (d-Phe) with a selectivity coefficient KDL=5.75×10−4 and the limit of detection (LOD) is 1.37 μM, which reveals its good enantioselectivity and sensitivity.Graphical abstractHighlights► We have fabricated a hybrid chiral MIP sensor in one step. ► The electropolymerization begin with a pendant polymer precursor to form MIP. ► The hybrid MIP gives better adhesion for sensitive layer to contact with electrode. ► The adjustable structure of MIP improved the selectivity and stability of sensor. ► The sensor has good sensitivity and highly selectivity for l-Phenylalanine detection.
Co-reporter:Lan Xu, Jingya Hou, Yuanyuan Yang, Bingxin Li and Shaozhu Chen
Analytical Methods 2012 vol. 4(Issue 3) pp:807-811
Publication Date(Web):23 Feb 2012
DOI:10.1039/C2AY05820K
A novel ion-selective electrode for chiral determination of mandelic acid (MA) is constructed of a poly(vinyl chloride) (PVC) membrane doped with a chiral salen Mn(III) compound as chiral selector and coated with a chemically generated film of polyaniline (PANI). The developed sensor displays a linear response towards L-MA over a wide concentration range of 1.0 × 10−1 to 1.0 × 10−6 M with Nernstian slope of 57.6 mV per decade and the detection limit of 2.1 × 10−7 M. Ascribed to the hydration of PANI, it demonstrates a better potentiometric characteristic (especially, linear range, detective limit, response time) in contrast to the uncoated membrane based sensor.
Co-reporter:Yuanyuan Yang;Shaozhu Chen
Macromolecular Rapid Communications 2011 Volume 32( Issue 7) pp:593-597
Publication Date(Web):
DOI:10.1002/marc.201000806
Co-reporter:Yaqiong Wang, Yuanyuan Yang, Lan Xu, Jin Zhang
Electrochimica Acta 2011 Volume 56(Issue 5) pp:2105-2109
Publication Date(Web):1 February 2011
DOI:10.1016/j.electacta.2010.11.077
Molecularly imprinted, ordered mesoporous silica was synthesized using bisphenol A (BPA) as the template and 3-aminopropyltriethoxysilane modified with hexagonally structured mesoporous silica (SBA-15) as the carrier. Carbon paste sensors were constructed by mixing the molecularly imprinted, ordered mesoporous silica with graphite powder and paraffin oil, and they were found to detect bisphenol A (BPA) with enhanced selectivity due to their ordered mesoporous structure and their successful molecular imprinting. The linear range for the proposed sensor was 1.000 × 10−7 mol L−1 to 5.000 × 10−4 mol L−1, and the detection limit was determined to be 3.222 × 10−8 mol L−1. Overall, the sensor detected the water samples with satisfactory results.
Co-reporter:Shaozhu Chen, Lan Xu, Yuanyuan Yang, Bingxin Li and Jingya Hou
Analytical Methods 2011 vol. 3(Issue 10) pp:2374-2378
Publication Date(Web):16 Sep 2011
DOI:10.1039/C1AY05310H
A newly designed crosslinked polyaniline (CPAN) was developed and preliminarily used to fabricate a sensor for determination of ascorbic acid (AA). The nanostructured copolymer was confirmed through surface morphology studies (SEM). The amperometric response of electrodes toward AA based on crosslinked polyaniline (CPAN) is far more than that of linear polyaniline (LPAN), which exhibits improved electrocatalytic oxidation of AA. The linear range of the promising sensor is from 5.0 × 10−6 to 1.13 × 10−2 M with a lower detection limit of 1.67 × 10−6 M (S/N = 3) as well as good selectivity, stability and reproducibility.
Co-reporter:Jin Zhang, Yaqiong Wang, Ruihong Lv, Lan Xu
Electrochimica Acta 2010 Volume 55(Issue 12) pp:4039-4044
Publication Date(Web):30 April 2010
DOI:10.1016/j.electacta.2010.02.021
Amperometric detection of tolazoline (TL) was carried out on a gold nanoparticles (AuNPs)/poly-o-aminothiophenol (PoAT)-modified electrode by a molecular imprinting technique and electropolymerization method. The modification procedure was characterized via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The recognition between the imprinted sensor and target molecule was observed by measuring the variation of amperometric response of the oxidation-reduction probe, K3Fe(CN)6 on electrode. Under the optimal experimental conditions, the peak currents were proportional to the concentrations of tolazoline in two ranges of 0.05–5.0 μg mL−1 and 5.0–240 μg mL−1 with the detection limit of 0.016 μg mL−1. Meanwhile the prepared sensor showed sensitive and selective binding sites for tolazoline. The enhancement of sensitivity was attributed to the presence of AuNPs which decreased the electron-transfer impedance.
Co-reporter:Ruihong Lv;Xinhua Huang;Yaqiong Wang ;Jin Zhang
Journal of Applied Polymer Science 2010 Volume 115( Issue 1) pp:198-203
Publication Date(Web):
DOI:10.1002/app.31037
Abstract
A uniformly sized molecularly imprinted polymer for the peripheral vasodilator drug tolazoline (T-MIP) was prepared, and a nonimprinted polymer (NIP) was also synthesized in the same way but in the absence of the template. The T-MIP was prepared with methylacrylic acid as functional monomer and ethylene glycol dimethacrylate as crosslinker by a multistep swelling and polymerization method. These imprinted materials were characterized by scanning electron microscopy, nitrogen adsorption, and static adsorption experiments. Binding studies were also performed to evaluate the uptake of T-MIP and NIP with the results that T-MIP had a significantly higher binding capacity for tolazoline (T) than did NIP. The maximum static adsorption capacities of T-MIP and NIP for T were 78.9 and 38.8 μmol/g, respectively. The T-MIPs and NIPs were used as stationary phases of solid-phase extraction (SPE), and a relative selectivity coefficient (k′) value of 5.21 was obtained, which showed that the T-MIP sorbent had higher selectivity than the NIP sorbent. The method was applied to the determination of T in urine samples. The prepared polymer sorbent showed promise for SPE for gas chromatography determination of T in urine samples. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Lan Xu;Ruihong Lv;Yaqiong Wang ;Jiuzhi Gao
Journal of Applied Polymer Science 2010 Volume 118( Issue 2) pp:881-886
Publication Date(Web):
DOI:10.1002/app.32352
Abstract
The molecularly imprinted polymers (MIP) for drug naphazoline (NAZ) have been synthesized by precipitation polymerization. The effect of the dispersive solvents dichloromethane (DCM), acetonitrile (ACN), and Methanol (MeOH) on particle size and morphology of MIP (P1, P2, and P3) was investigated by scanning electron microscopy (SEM). The selectivity of P1, compared with nonimprinted polymer (NIP), C8 and C18 were evaluated via static adsorption using UV spectrophotometer. The result showed that the bond amount of P1 for NAZ was significantly higher than other sorbents. The P1 were applied as a solid-phase extraction (SPE) stationary phase to extract the NAZ from nasal drops and recoveries of more than 89% (relative standard deviations, RSD <5%) were obtained by high performance liquid chromatograph (HPLC) analyses. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Lan Xu, Yuanyuan Yang, Yaqiong Wang, Jiuzhi Gao
Analytica Chimica Acta 2009 Volume 653(Issue 2) pp:217-221
Publication Date(Web):27 October 2009
DOI:10.1016/j.aca.2009.09.007
A new enantioselective potentiometric sensor containing chiral salen Mn(III) as the chiral selector was designed for the assay of l-mandelic acid (l-MA). Optimized membrane electrodes displayed linear dynamic range from 1 × 10−5 to 1 × 10−1 mol L−1 with a detection limit of 7.2 × 10−6 mol L−1 and a Nernstian response of −58.1 ± 0.5 mV decade−1 towards l-MA within pH range 7.0–10.2. The potentiometric enantioselectivity coefficient (log KL,DPot) of this sensor was −4.0, indicating that the chiral salen Mn(III) complex-based electrode exhibited fairly good discrimination toward l-MA over counter isomer d-MA. The mechanism of chiral recognition for l-MA is discussed by using HF/STO-3G calculation method simulation.
Co-reporter:
Analytical Methods (2009-Present) 2012 - vol. 4(Issue 3) pp:
Publication Date(Web):
DOI:10.1039/C2AY05820K
A novel ion-selective electrode for chiral determination of mandelic acid (MA) is constructed of a poly(vinyl chloride) (PVC) membrane doped with a chiral salen Mn(III) compound as chiral selector and coated with a chemically generated film of polyaniline (PANI). The developed sensor displays a linear response towards L-MA over a wide concentration range of 1.0 × 10−1 to 1.0 × 10−6 M with Nernstian slope of 57.6 mV per decade and the detection limit of 2.1 × 10−7 M. Ascribed to the hydration of PANI, it demonstrates a better potentiometric characteristic (especially, linear range, detective limit, response time) in contrast to the uncoated membrane based sensor.
Co-reporter:Shaozhu Chen, Lan Xu, Yuanyuan Yang, Bingxin Li and Jingya Hou
Analytical Methods (2009-Present) 2011 - vol. 3(Issue 10) pp:NaN2378-2378
Publication Date(Web):2011/09/16
DOI:10.1039/C1AY05310H
A newly designed crosslinked polyaniline (CPAN) was developed and preliminarily used to fabricate a sensor for determination of ascorbic acid (AA). The nanostructured copolymer was confirmed through surface morphology studies (SEM). The amperometric response of electrodes toward AA based on crosslinked polyaniline (CPAN) is far more than that of linear polyaniline (LPAN), which exhibits improved electrocatalytic oxidation of AA. The linear range of the promising sensor is from 5.0 × 10−6 to 1.13 × 10−2 M with a lower detection limit of 1.67 × 10−6 M (S/N = 3) as well as good selectivity, stability and reproducibility.
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