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 2 V(vs. Ag/AgCl) held for 1 s and 2 s, 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 2 V (vs. Ag/AgCl) with the two enantiomers being present at the same concentration (10 mM). 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对映体选择性识别d和l苯丙氨酸的电化学传感器，其中吡咯的电聚合通过计时电位法（CP）进行，目标分子存在于Ag丝网印刷电极的表面。 （SPE）表面。通过在0 V和2 V（vs。Ag / AgCl）下分别保持1 s和2 s的20周期的多电势步骤（两个对映异构体以相同的浓度存在）来评估传感性能。l和d的个体选择性-根据0和2 V（vs. Ag / AgCl）之间的电流变化，估计其各自压印膜上的苯丙氨酸分别为L / D = 23.480±2.844 / 1和D / L = 19.134±1.870 / 1。两种对映异构体以相同的浓度（10 mM）存在。研究了影响识别能力的几个参数，包括：d和l的交叉选择性-苯丙氨酸印迹膜，苯丙氨酸浓度效应，干扰物质，失活和电极的储存寿命。苯丙氨酸印迹膜的特征还在于交流阻抗，计时电流法，傅立叶变换红外光谱（FTIR），扫描电子显微镜（SEM）和能量色散X射线光谱（EDS）。最后，提出了一种在正负电势作用下聚吡咯膜与其模板相互作用的识别机制。