Electroactivated Fullerol-gold nanocluster@histidine nanocomposite for nitrite sensing with wide linear range and ultralow detection limit

Establishing a rapid and sensitive approach for the detecting (NO 2 − ) is of great importance in environmental pollution monitoring and human health protection. Herein, a Fullerol-gold nanocluster@histidine (FLN-AuNCs@His) nanocomposite has been synthesized and utilized as an effective electrochemical sensing material for NO 2 − analysis. The FLN-AuNCs@His nanocomposite and the sensing interface were characterized by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), and electrochemical techniques . Electrochemical experiments show that the FLN-AuNCs@His after electrochemical activation in 0.1 M KCl show significantly enhanced electrocatalysis for the oxidation of NO 2 − . From the physical and electrochemical characterization, the promotion effect is ascribed to the increase of electrocatalytic active sites and the electro-conductivity through the electroactivation. Under the optimal conditions, the catalytic currents showed a good linear relationship with the concentration of NO 2 − in a wide range from 10.0 nM to 10.0 mM with an ultralow detection limit of 1.98 nM (S/N = 3). The sensor is applicable for the analysis of NO 2 − extracted from the soil samples, suggesting its potential application value in environmental sample analysis.