Department of Chemical Engineering, I-Shou University, Ta-Hsu Hsiang, Kaohsiung 84008, Taiwan.
Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80782, Taiwan.
Biosens Bioelectron. 2018 May 15;105:143-150. doi: 10.1016/j.bios.2018.01.010. Epub 2018 Jan 6.
In this study, electrochemical sensors for the enantioselective recognition of d and l phenylalanine were prepared using a molecular imprinting technique in which the electro-polymerization of pyrrole was carried out by Chronopotentiometry(CP) with the target molecules being present on a Ag screen printed electrode's (SPE) surface. The sensing performance was evaluated by multi-potential steps at 0 and 2V(vs. Ag/AgCl) held for 1s and 2s, respectively, for 20 cycles (with the two enantiomers being present at the same concentration). The individual selectivity's for l and d- phenylalanine on their respective imprinted films were estimated to be L/D = 23.480 ± 2.844/1 and D/L = 19.134 ± 1.870/1 respectively, based on the current change between 0 and 2V (vs. Ag/AgCl) with the two enantiomers being present at the same concentration (10mM). Several parameters affecting recognition ability were investigated including: cross-selectivity of d and l- phenylalanine imprinted film, phenylalanine concentration effects, interfering species, deactivation and the storage life of electrode. The phenylalanine imprinted films were also characterized by AC impedance, chronoamperometry, Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscope(SEM), and Energy Dispersive X-Ray Spectroscopy (EDS). Finally, a recognition mechanism for the interaction of the polypyrrole film with its template under the influence of applied negative and positive potentials is proposed.
在这项研究中，使用分子印迹技术制备了用于对 d 和 l 苯丙氨酸进行对映选择性识别的电化学传感器，其中通过恒电流计时电位法（CP）进行吡咯的电聚合，目标分子存在于 Ag 丝网印刷电极（SPE）的表面上。通过在 0 和 2V（相对于 Ag/AgCl）下进行多电位步，分别保持 1s 和 2s，进行 20 个循环（两种对映体以相同浓度存在）来评估传感性能。基于在相同浓度（10mM）下两种对映体存在时，在 0 和 2V（相对于 Ag/AgCl）之间的电流变化，估计 l 和 d-苯丙氨酸在各自印迹膜上的个体选择性分别为 L/D = 23.480 ± 2.844/1 和 D/L = 19.134 ± 1.870/1。研究了影响识别能力的几个参数，包括：d 和 l-苯丙氨酸印迹膜的交叉选择性、苯丙氨酸浓度效应、干扰物质、失活和电极的存储寿命。还通过交流阻抗、计时电流法、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和能量色散 X 射线光谱（EDS）对苯丙氨酸印迹膜进行了表征。最后，提出了在施加负电和正电的影响下，聚吡咯膜与模板相互作用的识别机制。
