Enhanced glutathione sensing in clinical samples with Bovine Serum Albumin-stabilized copper nanoclusters: A novel fluorescent probe

Glutathione (GSH) is a critical biomolecule involved in maintaining protecting against both oxidative stress and cellular redox homeostasis, making its accurate detection essential for clinical diagnostics. This study introduces a novel, highly sensitive, and selective fluorescence-based method for detecting GSH in human serum samples, using copper nanoclusters stabilised with Bovine Serum Albumin (BSA-CuNCs) as a probe. The BSA-CuNCs display a distinct fluorescence emission peak at 402 nm when excited at 326 nm, demonstrating exceptional photostability and structural integrity. The interaction with GSH not only significantly enhances the fluorescence intensity but also induces a red shift in the emission peak, attributed to the chemisorption of GSH onto the BSA-CuNCs surface, as confirmed by IR, TEM, and EDS analyses. This method achieves a broad linear detection range spanning from 2.95 to 207 µM and a highly sensitive detection limit of 79 nM, outperforming many existing detection techniques with respect to both selectivity and sensitivity. The BSA-CuNCs probe has been effectively used to measure the amount of GSH in human serum, with recovery values between 95.07 % and 101.38 %. Furthermore, the experimental results have been confirmed by density functional theory (DFT) calculations and molecular docking, yielding a full comprehension of the interaction mechanisms at the molecular scale. The novelty of this approach lies in its combination of high selectivity, sensitivity, and biocompatibility, making it a valuable tool for the early monitoring and diagnosis of diseases related to oxidative stress, such as cancer and neurodegenerative disorders. The method’s simplicity, cost-effectiveness, and potential for adaptation to other biological targets underscore its significance.