A sensitive voltammetric sensor for determination of Cd(II) in human plasma

Abstract

The development of electrochemical sensors via surface modification has attracted considerable attention as a low-cost method to the sensitive detection of a variety of analytes. In addition, the surface modification of electrodes has been directed toward several goals, often involving electrode kinetics and chemical selectivity. In this study, we performed the electrochemical modification of glassy carbon (GC) electrode with 2-thiolbenzimidazole (2-TBI). The developed electrode was characterized by the reflection–absorption infrared spectroscopy (RAIRS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). According to the RAIRS results, the binding type of the 2-TBI to glassy carbon electrode was through the etheric linkage. The working range of the developed electrode was also studied. In addition, the developed electrode was applied to human plasma samples for the determination of Cd(II). The linearity range of Cd(II) was obtained as 1.0×10−11–2.5×10−10M with the detection limit (S/N=3) of 2.40×10−12M.