Abstract: For the first time,the present work describes a highly sensitive and selective method for enantioselective determination of S-ornidazole (S-ONZ), which is based on conducting polymerpolysiloxane duplex molecularly imprinted membrane (DMIM) modified carbon paste electrode (CPE). In this method,a conductive copolymer layer with groups of-Si(OCH_3)_3 and borate B(OH)_2 was firstly electrodeposited on the surface of CPE using 3-(phenylamino) propyltrimethoxysilane (PMTEOS)and 2-aminophenylboronic acid (2-APBA) as monomers,and then a molecularly imprinted polysiloxane membrane was covalently formed over the as-constructed conductive copolymer layer via a sol-gel process in the presence of 3-aminopropyltrimethoxysilane (as functional monomer),tetraethyl orthosilicate (as cross-linker) and S-ONZ (as template). The additional coordinate interaction introduced by B (III) has endowed the sensor with intensive enantioselectivity and high affinity toward the template S-ONZ. Under optimum conditions,the reduction peak currents of S-ONZ by differential pulse voltammetry were linear to S-ONZ concentrations in the range from 6.0 x 10~(-8) to 3.5 x 10~(-4) mol/L with a detection limit of11 nmol/L. The as-prepared sensor has been successfully applied for detecting S-ONZ in pharmaceutical and biological samples with good precision (RSD 3.3% ~ 4.2%) and acceptable recoveries (95.1% ~ 106%).
Template and target information: S-ornidazole, S-ONZ