Ion Selective Electrode Mediated by Transfer Layer of Graphene Oxide for Detection of Ca²⁺with Highly Sensitivity and Selectivity

A Ca2+ selective microelectrode was proposed through electrodepositing graphene oxide (GO) on carbon fiber as an efficient ionelectron transfer layer. The gold leaves were further synthesized at GO surface to increase the specific surface area, and provide a substrate for assembly of the specific ligands for Ca2+. GO with negatively charges greatly facilitated the electron transfer process from the recognition center to electrode surface, resulting in the apparently enhanced sensitivity towards Ca2+. Moreover, the developed ion-selective microelectrode exhibited good selectivity to Ca2+, and a good linear range from 10 μM to 10 mM with a detection limit of 5.91 ± 0.46 μM.