Zn-doped carbon dots-based versatile bioanalytical probe for precise estimation of antioxidant activity index of multiple samples via fenton chemistry

Abstract

The significance of antioxidant activity determination in health sciences and food technology has become a hot research area as it is directly related to oxidative stress which is affiliated with several diseases and food deterioration. Herein, we fabricated a Zn-CDs-based (Zn-doped carbon dots-based) bioanalytical probe for the estimation of antioxidant activity index (AAI) to cope with the truncated robustness, high interference effect in complex samples, photo-bleaching, and low stability of the traditional techniques. Besides, the novel AAI standardized the presentation of the results by considering the transducer, Zn-CDs, concentration as reported results vary diversely for the same sample. In principle, free radicals quenched the fluorescence of the probe via inner filter effect and dynamic quenching. The presence of antioxidants hindered the fluorescence quenching by sequestering the free radicals from the reaction. The designed nanoreagent was validated for its applications using ascorbic acid, human serum, topical cosmetic formulation, and tomato juice samples. The bioanalytical probe demonstrated precise linearity, high robustness, low interference effect, and analytical equivalence when compared to the DPPH free radical assay. Hence, it can be used for the diagnosis and follow-up of oxidative stress-related ailments, developing and characterizing cosmeceuticals, analysis of antioxidant-containing formulations, and assessing and controlling the quality of food products. It is the first report to explore the antioxidant feature of Zn-CDs and its advantage for the estimation of AAI.