Carbon nitride dots can serve as an effective stabilizing agent for reduced graphene oxide and help in subsequent assembly with glucose oxidase into hybrids for glucose detection application

The carbon nitride dots (CNDs) can serve as an effective stabilizing agent for reduced graphene oxide (GO) prepared by chemical reduction using hydrazine hydrate as the reducing agent. Physicochemical characterization with a combination of techniques including UV–vis spectroscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy indicate the preparation of aqueous dispersion of rGO and the formation of CNDs–rGO hybrids. We further demonstrate the subsequent self-assembly of the CNDs–rGO with glucose oxidase (GOD) into hybrids, which is confirmed by the scanning electron microscopy and electron energy dispersive spectrum analysis. As a typical application of such materials, a glucose biosensor has been constructed by deposition of the GOD–CNDs–rGO hybrids on the surface of a glassy carbon electrode. The linear detection range and detection limit are estimated to be from 40 μM to 20 mM (r = 0.994) and 40 μM at signal-to-noise ratio of 3, respectively. It is further shown that this glucose biosensor can be used for glucose detection in human blood serum.