Hydrothermally synthesized magnesium phosphate decorated with graphene oxide hybrid composite for high-performance electrochemical detection of Trolox

Abstract

Trolox (TRX), a synthetic form of vitamin E, is used as a standard antioxidant reference substance in total antioxidant capacity (TAC) testing. Its detection is crucial not only for estimating the nutritional quality of antioxidant-rich foods but also for biomedical monitoring of oxidative stress-related disorders. This compound has garnered significant scientific interest due to its ability to neutralize reactive oxygen species (ROS) and its critical role in cellular defense mechanisms against oxidative stress. This work investigated the improvement of the electrochemical performance of hydrothermally synthesized Mg₂P₂O₇ by incorporating graphene oxide (GO), resulting in the formation of a Mg₂P₂O₇@GO composite for an electrochemical sensor. The working principle of the electrochemical sensor is that GO enhances the surface area and electrical conductivity of the composite, and Mg₂P₂O₇ facilitates the redox reaction of the antioxidant TRX by accelerating electron transfer kinetics, which results in greater sensitivity and selectivity towards the detection of TRX. The Mg₂P₂O₇@GO/GCE electrode also shows a wide linear range (0.1–994.6 μM), low detection limit (0.01 μM), high sensitivity (0.64 μA μM⁻¹ cm⁻²), selectivity, reproducibility, and stability for the detection of TRX. The preparation of Mg₂P₂O₇ and formation of the Mg₂P₂O₇@GO composite were successfully characterized using different analytical instruments. Electrochemical analyses, e.g., cyclic voltammetry and electrochemical impedance spectroscopy, explored the enhanced electrochemical behavior of the modified electrode. Moreover, the sensor was successfully utilized to analyze TRX in actual samples such as almonds and peanuts, proving its feasibility in actual samples. These results indicate the potential of the Mg₂P₂O₇@GO composite as a useful and selective electrochemical platform for the analysis of TRX, which is a critical biomarker in monitoring oxidative stress-related diseases.