Networked cobaltous phosphate decorated with nitrogen-doped reduced graphene oxide for non-enzymatic glucose sensing

Abstract

Co3(PO4)2 is recently reported to be an attractile electrocatalyst in biomonitoring oxygen/hydrogen evolution due to its biocompatibility and high stability. In this work, a weakly networked cobaltous phosphate (net-Co3(PO4)2) decorated with defective nitrogen-doped reduced graphene oxide (net-Co3(PO4)2/NG) was facilely prepared through ultrasonic exfoliation. A glassy carbon electrode (GCE) modified with the net-Co3(PO4)2/NG (net-Co3(PO4)2/NG) was fabricated as a non-enzymatic glucose sensor. The net-Co3(PO4)2/NG/GCE exhibited a ultra-high sensitivity of 2307 μA mM−1 cm-2, a low detection limit of 1.0 μM (at a signal-to-noise ratio of 3, S/N = 3). The excellent electrochemical performances of net-Co3(PO4)2/NG/GCE for glucose oxidation were attributed to the superior catalytic activity of net-Co3(PO4)2 with a weakly bonding structure because of solvent exfoliation, and the high conductivity of defective NG sheets. Moreover, the net-Co3(PO4)2/NG/GCE was successfully used to detect glucose in human serum, and the good recoveries made net-Co3(PO4)2/NG a very promising sensing material in clinical lab.