Zinc oxide nanoparticles decorated nitrogen doped porous reduced graphene oxide-based hybrid to sensitive detection of hydroxychloroquine in plasma and urine.

The antimalarial hydroxychloroquine (HCQ) has considered for the treatment of systemic lupus erythematosus. Moreover, HCQ has been used as a drug to treat Coronavirus disease (COVID-19). In this work, nitrogen doped porous reduced graphene oxide (NprGO) has been prepared via environmentally friendly process using Fummaria Parviflora extract. A catalyst based on ZnO nanoparticles-nitrogen doped porous reduced graphene oxide (ZnO-NprGO) was prepared by hydrothermal method and characterized. The diameter of ZnO nanoparticles was ~22-37 nm, which were inserted between the NprGO sheets effectively prevented their aggregation. The ZnO-NprGO hybrid had high surface area and good electro-catalytic property, suiting for determination of HCQ. The ZnO-NprGO modified carbon paste electrode (CPE)-based sensor operated in a wide concentration range of 0.07-5.5 μmol L with low limit of detection of 57 nmol L and sensitivity of 14.175 μA μmol L. Remarkably, the ZnO-NprGO/CPE sensor indicated acceptable accuracy, reproducibility, and stability. In addition, the proposed sensor was applied to detection of HCQ in biological samples and the recoveries were 92.0-102.5%, with relative standard deviations of 1.9-4.3%. The unique physical structure of ZnO-NprGO, as well as its chemical and electrical properties, make it promising interface for use in sensors and nanoelectronic applications.