▎ 摘　　要

The accurate determination of oxidative stress biomarker 3-nitro-L-tyrosine (3-NT) in biological medium is of high medical significance. Here, we report an electrochemical sensor for 3-NT using CdWO4 nanodots decorated reduced graphene oxide nanocomposite (CdWO4 ND@RGO) modified screen-printed electrode. The morphological and structural aspects of the composite were analyzed using transmission electron microscopy, Energydispersive X-ray spectroscopy, Raman, and X-ray diffraction techniques. The electrochemical and interfacial properties were tested via voltammetry and impedance measurements, respectively. The CdWO4 ND@RGO was coated on a screen-printed electrode, and the resulting modified electrode displays excellent electrocatalytic ability to 3-NT. An amperometric sensor was fabricated which displayed good sensitivity in the linear range of 18.5 nM-1.84 mM. The detection limit was 3.24 nM (S/N= 3) which surpassed the limits of many existing methods Most of the previously reported 3-NT sensors depends on expensive analytical methods, whereas, the described method is a simple, low-cost, easy-to-make modified electrode that works well even in real samples such as human serum and urine.