Enantioselective determination of S-ornidazole by using carbon paste electrode modified with boron-embedded conductive copolymer-polysiloxane-based molecularly imprinted hybrid film

Highly selective determination of enantiomers by electrochemical sensors with simple recognition elements is of great interest in pharmaceutics, biochemistry and medical fields. The present work developed an innovative electrochemical sensor, which based on boron-embedded molecularly imprinted hybrid film (B-MIHF) modified carbon paste electrode (CPE), for enantioselective determination of S -ornidazole ( S -ONZ). A boron-embedded conductive copolymer was firstly electro polymerized on carbon paste electrode (CPE), and then molecularly imprinted polysiloxanes (MIP) were hydrolyzed and condensed over the conductive copolymer layer via a sol-gel process. The as-prepared B-MIHF, comprised the advantages of boron-embedded conductive copolymer and molecularly imprinted polysiloxanes, could not only implement direct signal transformation between imprinted cavities and sensing elements, but show amazing selectivity to template S -ornidazole. Above all, the introduction of coordinate interaction formed between trisubstituted boron atoms embedded in B-MIHF matrix and nitrogen atoms of template endow the sensor with intensive enantioselectivity. Under optimum experiments conditions, the reduction peak currents of S -ONZ by differential pulse voltammetry were linear to S -ONZ concentrations in the range from 6.0   ×   10 −8 to 1.0   ×   10 −6   mol   L −1 and 1.0   ×   10 −6 to 3.5   ×   10 −4   mol   L −1 with a detection limit of 1.1   ×   10 −8   mol   L −1 . The B-MIHF-based sensor has been successfully applied for the determination of S -ONZ in pharmaceutical and biological samples with good precision (RSD 2.25–4.11%) and acceptable recoveries (96.00–108.00%).