Chiral voltammetric sensor for warfarin enantiomers based on carbon black paste electrode modified by 3,4,9,10-perylenetetracarboxylic acid

Abstract

A chiral electrochemical sensor based on carbon black paste electrode (CBPE), consisting of graphitized carbon black powder Carboblack C modified by nanoclusters of 3,4,9,10-perylenetetracarboxylic acid (PTCA) for the selective recognition and determination of warfarin (WA) enantiomers is described in this work. The spontaneous appearance of two-dimensional space group during self-assembly by an external induction of PTCA nanoclusters provides their chirality. It was found that the CBPE modified by PTCA afforded specific interaction with WA enantiomers and acted as a chiral selector, which affected the current and peak potential change. CBPE modified by PTCA was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The electrochemical and analytical characteristics of the sensor, and conditions of the voltammogram registration were studied by differential pulse voltammetry (DPV). The experimental results indicate a linear correlation between the peak current of warfarin enantiomers and their concentration in the range from 5 μM to 0.16 mM, leading to a detection limit of 3.09 μM and 4.02 μM for R- and S-WA, respectively. The potential ability of proposed electrode for WA enantiomer determinations has been evaluated by analyzing human urine and blood plasma with a recovery ranging from 97.1% to 102.9%. The present sensor can determine ratio of WA isomer's in enantiomeric mixture.