A novel electrochemiluminescence sensor for the determination of diphenidol based on a nano-TiO2/silica sol/PVP/Ru(bpy)32+ modified gold electrode

Abstract

An electrochemiluminescence (ECL) method was developed for the determination of diphenidol based on the sensitizing effect of diphenidol on Ru(bpy)₃²⁺, and a nano-TiO₂/silica sol/PVP/Ru(bpy)₃²⁺ modified gold electrode was prepared for the simple, sensitive and accurate determination of diphenidol; moreover, both the electrochemical behavior and the electrochemical luminescence behavior of Ru(bpy)₃²⁺ and Ru(bpy)₃²⁺–diphenidol were investigated. The results show that the proposed electrode possessed very good electrochemical activity and electrochemiluminescence response to the Ru(bpy)₃²⁺–diphenidol system under the optimum experimental condition, and the linearity of diphenidol concentration to ECL intensity was achieved in the concentration of diphenidol from 1.0 × 10⁻⁷ mol L⁻¹ to 1.0 × 10⁻⁴ mol L⁻¹ and the detection limit (S/N = 3) was 6.49 × 10⁻¹⁰ mol L⁻¹. Through the parallel determination of 1.0 × 10⁻⁵ mol L⁻¹ diphenidol for 7 times, the RSD of results was 3.00%; moreover, the recovery ranging from 96.4% to 105.6% was obtained in the detection of diphenidol tablets and the RSD was 3.75% (n = 5). The proposed method exhibited high selectivity and sensitivity, and the procedure was simplified for sample processing; thus, it could be applied for the analysis of diphenidol with satisfactory results.