C-C Bonding of Graphene Oxide on 4-Aminophenyl Modified Gold Electrodes towards Simultaneous Detection of Heavy Metal Ions

This paper studied the electrochemical sensors based on C-C bonding of graphene oxide (GO) on π-conjugated aromatic group modified gold electrodes for simultaneous detection of heavy metal ions. For comparison, another sensing interface Au-Ph-NH-CO-GO, in which GO was modified to Au-Ph-NH₂ interfaces by amide bonding. On the basis of the principle of heavy metal ions complexation with oxygenated species on GO, the fabricated sensing interfaces were used for the simultaneous determination of Pb²⁺, Cu²⁺ and Hg²⁺. The performance of two sensing interfaces for simultaneous detection of three metal ions was compared. Au-Ph-GO sensing interface demonstrated higher sensitivity and better repeatability than Au-Ph-NH-CO-GO sensing interface.