A new electron transfer mediator actuated non-enzymatic nitrite sensor based on the voltammetry synthetic composites of 1-(2-pyridylazo)-2-naphthol nanostructures coated electrochemical reduced graphene oxide nanosheets

As efficient electron transfer mediator, various nanomaterials with smart performance have been explored in non-enzymatic sensor fabrication. We herein present an electron transfer mediator actuated electrochemical non-enzymatic sensor to assay nitrite, enabled by electrochemical reduced graphene oxide (ERGO) and 1-(2-pyridylazo)-2-naphthol (PAN). The composites of PAN-ERGO coating on electrode surface were successfully fabricated through a facile and green cyclic voltammetry technique. With the aid of ERGO nanosheets on the electrode surface, the electron transfer mediator of PAN nanostructures was easily immobilized and hybridized with ERGO, resulting in a remarkably synergistic effect between ERGO sensing substrate and the electrodeposited PAN coating for target electron transfer. The results demonstrated that the electrocatalytic current increased linearly with the nitrite concentration in the range of 7.49-1752.6 μM and 1752.6-3500 μM, with a good detection limit of 0.67 μM and 1.44 μM (signal-to-noise ratio, S/N = 3), respectively. The present work provide some new insights for the smart design of high efficiency electrocatalytic materials that based on the composites of electrochemical reduced graphene oxide and other substances.