Simultaneous Ultrasensitive Detection of Toxic Heavy Metal Ions Using bis(imidazo[4,5-f][1, 10]phenanthroline) Appended bis-triazolo Calix[4] Arene (8)/Glassy Carbon Electrode

Abstract

A highly sensitive and selective electrochemical sensor has been developed and investigated for multiple metal ions detection. The GCE was modified with the synthesized multifunctional calix[4]arene and the anodic stripping voltammetry was used for the simultaneous electrochemical analysis of Cd2+, Pb2+ and Hg2+ ions. The analysis conditions were optimized with respect to modifier's loaded concentration, accumulation time, potential, supporting electrolyte and pH of the media. The bis(imidazo[4,5-f][1, 10]phenanthroline) appended bis-triazolo Calix[4] arene modified glassy carbon electrode (compound (8)/GCE) exhibited fast electron transfer rate for the stripping signals of Cd2+, Pb2+ and Hg2+ ions as evidenced from square wave anodic stripping voltammograms. The linear calibration curves were used for the evaluation of the detection limits with values of 0.037, 0.015 and 0.025 nM for Cd2+, Pb2+ and Hg2+ respectively. The modified electrode showed the qualities of repeatability, reproducibility and selectivity for Cd2+, Pb2+ and Hg2+ in the presence of common competitive metal ions. The study was extended to real water samples by sensing the traces of given metal cations in locally collected drinking water samples. The results reveal that the compound (8)/GCE is an extremely sensitive, cheap and portable electrochemical platform for the detection of multiple heavy metal ions in the drinking water reservoirs and seawater.