Determination of trace cadmium with thiol functionalized graphene modified glassy carbon electrode.

The detection method of trace amounts of cadmium was established based on thiol functionalized graphene modified glassy carbon electrode. The graphene oxide prepared by Hummers method was modified through bromoacetic acid carboxylation, hydrazine reduction, acylation reaction, and then reacted with 2-mercaptoethanol to produce thiol functionalized graphene. X-ray photoelectron spectroscopy and Raman spectroscopy were used to characterize the produced functionalized graphene. Heavy metal sensor was prepared by thiol functionalized graphene modified glassy carbon electrode. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to study the electrochemical behavior of the modified electrode. Combined modified glassy carbon electrode with differential pulse stripping voltammetry, a method for detecting trace amounts of cadmium was established. The results showed that at optimal conditions, the linear calibration curves ranged from 1×10^-9-150×10^-9 for Cd²⁺ with the linear correlation coefficient of 0.993, the detection limit was estimated to be around 0.015×10^-9 (S/N = 3) and it also showed a good reproducibility (RSD = 1.67%, n = 11). [ABSTRACT FROM AUTHOR]