Acid phosphate-activated glassy carbon electrode for simultaneous detection of cadmium and lead

Abstract

• Greatly enhanced electron transfer rate was realized by direct electrochemical activation of glassy carbon in acidic PB. • Phosphate anchored on activated glassy carbon was responsible for enrichment of metal ions. • The activated glassy carbon electrode can simultaneously monitor Cd 2+ and Pb 2+ with high sensitivity and low detection limit. • This electrode was featured with easy and fast eco-friendly activation process without adding extra reagents. Lead and cadmium are the most common toxic heavy metals exist in the environment, so it is of significant to develop highly efficient detection methods to monitor lead ions (Pb 2+ ) and cadmium ions (Cd 2+ ). In this work, a simple and eco-friendly electrochemical activation method, for the detection of Pb 2+ and Cd 2+ at trace concentration levels, was successfully utilized to activate the glassy carbon electrode (AGCE), and a great enhancement of the electron transfer ability was achieved. The effect of various activation conditions on electrochemical characteristics of AGCE and on the simultaneous current responses to Cd 2+ and Pb 2+ were investigated. Field emission scanning electron microscopy characterization revealed that phosphate was anchored on the activated glassy carbon surface. At the optimal condition, the AGCE could dual detect Cd 2+ and Pb 2+ with lowest detection limits of 17 and 0.3 nM, and linear concentration ranges of both in 0.05–5 µM. Furthermore, satisfactory recoveries in the analysis of real water samples were achieved, indicating the promising applicability of AGGE for real water monitoring.