Utilization of sodium montmorillonite clay for enhanced electrochemical sensing of amlodipine

Abstract

Nanosize surface of sodium montmorillonite has been prepared via sonication and deposited on glassy carbon electrodes for use as working electrode in a highly sensitive electrochemical biosensor for the detection of trace amounts of the calcium channel blocking drug, amlodipine. The cyclic voltammetric behaviour of amlodipine is studied in the pH range of 1.0−13.0. In alkali medium (pH 13.0) the sensor shows good response. Cyclic voltammograms show one oxidation peak and one broad reduction peak, which may be due to the oxidation of secondary amino group and reduction of chlorine and nitro groups respectively. Plots of log peak current and potential when correlated with log scan rate, indicate irreversible electron diffusion controlled redox reaction. The optimum conditions have been established by differential pulse stripping voltammetry. The anodic peak current is linear with concentration of the analyte at optimum conditions; the detection limit has been determined to be 0.01 mg/mL. A simple, sensitive and time-saving differential pulse stripping voltammetric procedure has been developed for estimation of amlodipine in its formulations as tablets.