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.