Development of Electrochemiluminecence Sensor for Verapamil Hydrochloride Based on TiO₂ sol/ZnO@Ag/Silica sol-Ru(bpy)₃²⁺ Modified Pyrolytic Graphite Electrode

Abstract

A sensitive solid-state electrochemiluminesence (ECL) sensor for verapamil hydrochloride (VpCl) was fabricated based on the film formability of TiO 2 sol and electrocatalysis of ZnO@Ag. The immobilization of tris(2, 2′bipyridine) ruthenium (II) (Ru(bpy) 3 2+) by using TiO 2 sol/ZnO@Ag/silica sol composite exhibited stable ECL behaviors, and a sensitive and selective method was developed for VpCl determination. Under the optimal conditions, the ECL response of the sensor showed a linear correlation to the concentration of VpCl in the range of 1.0 × 10 −7 -1.0 × 10 −4 mol L −1 (R 2 = 0.9832) with a detection limit of 7.00 × 10 −9 mol L −1 (S/N = 3). The RSD of ECL response was 2.07 % for 1.0 × 10 −5 mol L −1 VpCl under 10 continuous cyclic scans. The spiked recovery was 97.90-104.50 % for determination of real VpCl sample. The proposed method exhibited selectivity and sensitivity for VpCl, and improved efficiency of Ru(bpy) 3 2+ .