Sensitive and highly selective biosensor based on innovative V2O5 nanoparticles for detection of glutathione

In this study, V₂O₅ nanoparticles with flake or prism-like morphology were synthesized using a two-step solvothermal synthesis and calcination process for the first time. These nanoparticles exhibited intrinsic oxidase-like activity, catalyzing the oxidation of 3,3′,5,5′-tetramethylbenzidine to produce blue oxidized 3,3′,5,5′-tetramethylbenzidine even in the absence of H₂O₂, with a characteristic absorption peak at 652 nm. Upon the introduction of glutathione (GSH), the solution color gradually lightened, correlating with a reduction in absorbance. Leveraging these properties, we developed a simple, sensitive, and highly selective colorimetric biosensor utilizing V₂O₅ nanoparticles for GSH detection in human serum. The developed method demonstrated excellent linearity over a range of 1–30 μM, with a low detection limit of 4.04 nM. Additionally, it exhibited outstanding selectivity against common interfering substances in human serum. Furthermore, this biosensor enabled both naked-eye detection and spectrophotometric quantitative analysis of GSH. Successful application to spiked serum samples yielded recoveries ranging from 97.1% to 101.7%. Overall, this method offers a promising approach for determining GSH content in human serum, with significant potential for biomedical testing applications. Its rapid and accurate detection capability may contribute to early diagnosis and treatment of various fatal diseases, including cancer and cardiovascular diseases.