Fabrication of an ultrasensitive electrochemical sensor based on a mesoporous silica material functionalized by copper ion (SBA-15-Cu(II)) modified carbon paste electrode for determination of antibiotic ceftazidime and its application in pharmaceutical and biological samples

Abstract

A simple, sensitive and selective sensor based on carbon paste electrode modified by functionalized mesoporous silica material was developed for the electrochemical determination of ceftazidime (CFZ). The functionalized mesoporous silica was synthesized through a self-assembly process using triblock copolymer as template under acidic conditions and then incorporated in the carbon paste electrode as a modifier. This modifier was characterized by transmission electron microscopy, X-ray diffraction and scanning electron microscopy. The oxidation of CFZ was studied on modified carbon paste electrode using cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy (EIS). The results show that the oxidation peak current of CFZ on the modified carbon paste electrode was significantly improved compared to that obtained on the bare carbon paste electrode. Under optimum conditions, the sensor exhibited a linear response over the CFZ concentration range of 1–2500 nM, with a detection limit of 0.3 nM. The proposed sensor was successfully applied for monitoring of CFZ in the pharmaceutical and biological samples, and satisfactory results were obtained.