Direct electrodeposion of reduced graphene oxide and dendritic copper nanoclusters on glassy carbon electrode for electrochemical detection of nitrite

We have developed an effective strategy to fabricate a novel non-enzymatic nitrite sensor. Copper nanodendrites (Cu-NDs) and reduced graphene oxide (RGO) were successively deposited on glassy carbon electrode (GCE) via a simple and two-step electrodeposition method. The fabricated sensor showed an excellent electrocatalytic activity for nitrite reduction. Moreover, the effects of electrodeposition circles, Cu²⁺ concentration, pH value and detection potential on the current responses of Cu-NDs/RGO/GCE toward nitrite were optimized to obtain the maximal sensitivity. Under optimal experimental conditions, Cu-NDs/RGO/GCE demonstrated the low detection limit of 0.4 μM nitrite (signal-to-noise ratio, S/N = 3), the high sensitivity of 214μAmMH cmr², and the wide linear range from 1.25 x 10^-3 to 13mM. The superior response of the sensor to nitrite was mainly attributed to the enlarged surface-to-volume ratio with more electroactive sites and the synergistic effect of Cu-NDs and RGO. This work presented a feasible approach for future research in non-enzymatic amperometric sensors and other surface functionalizing.