Detection of nitrite in water using Glycine-modified nanocarbon and Au nanoparticles co-modified flexible laser-induced graphene electrode

In this work, we firstly developed a laser-induced graphene (LIG) electrode modified by gold nanoparticles (AuNPs) and glycine-modified nanocarbon (Gly-C), and used it to detect nitrite by linear scanning voltammetry. The physical and electrochemical characteristics of the electrodes were characterized using scanning electron microscopy, energy dispersive spectroscopy analysis, fourier transform infrared spectroscopy, and contact angle analysis. Our findings demonstrated that the electrocatalytic oxidation of nitrite can be enhanced by the successful loading of AuNPs, and Gly-C enhances electrode hydrophilicity and promotes nitrite adsorption capacity of the electrode surface. Under optimal conditions, the linear of the sensor is 7 ∼ 700 μg/L and 700 ∼ 1050 μg/L, and the detection limit is 0.84 μg/L. The anti-interference, repeatability, and stability of this sensor are outstanding. Recovery rates of the sensor in the actual groundwater and tap water varied from 94 to 123 %, and the relative standard deviation was less than 6.06 %. Our findings offer a potentially effective method for on-site monitoring of nitrite in aquatic environments.