An Ultra-sensitive Electrochemical Sensor for the Detection of Oxidative Stress Biomarker 3-Nitro-l-tyrosine in Human Blood Serum and Saliva Samples Based on Reduced Graphene Oxide Entrapped Zirconium (IV) Oxide

A sonochemical assisted preparation of zirconium dioxide (ZrO ₂ ) sheathed reduced graphene oxide (ZrO ₂ @rGO NCs) nanocomposites as the highly sensitive electrode material for the detection of oxidative stress biomarker 3-Nitro-l-tyrosine (3-NT) was reported. The formation of prepared ZrO ₂ @rGO NCs and its surface morphology were scrutinized by the X-ray photoelectron spectroscopy (XPS) and Field emission scanning electron microscope (FE-SEM). Moreover, the as-prepared nanocomposites were fabricated on the glassy carbon electrode (GCE), and its electrochemical performance towards the detection of 3-NT are studied by the various electrochemical techniques such as Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and amperometric ( i -t). The excellent conductivity of the rGO and the electrocatalytic properties of the ZrO ₂ significantly improves the electrochemical performances. As a result, the ZrO ₂ @rGO NCs display the LOD of 9 nM with the covering range of 0.025 to 855.2 μ M towards the detection of 3-NT. Finally, the real-time practicability of ZrO ₂ @rGO NCs in the spiked human serum and saliva samples also investigated, which shows the feasible found and recoveries. Hence, this study sonochemically prepared ZrO ₂ @rGO NCs provides the simple, rapid and efficient towards the detection of 3-NT in biological samples.