Dynamic detection of biothiols (Hcy, Cys, GSH) in mice under continuous hypoxia using highly selective electrochemical enzymatic biosensors.

Investigating the dynamics and conversion of biothiols, including homocysteine (Hcy), cysteine (Cys), glutathione (GSH) under hypoxia is critical for understanding their roles in redox homeostasis and hypoxia-related disease progression. Herein, electrochemical enzymatic biosensors (CSE@Pt/CNT/SPE, CDO1@AuNFs/rGO/SPE, GPx@PtPd/SPE) were developed for highly selective detection of Hcy, Cys, and GSH, respectively, with limits of detection (LODs) of 1.42, 0.38, and 0.19 μM. Moreover, the biosensors achieved sensitive plasma samples detection, and the performances are consistent with clinical biochemistry analyzer. They were further utilized for dynamic thiols analysis in mice under simulated hypoxia (15% O2), with increased Hcy and decreased Cys/GSH levels compared with normoxic controls. This verifies hypoxia-induced Hcy accumulation and enhanced antioxidant reactions, resulting in rapid Cys and GSH consumption. By comprehensive investigating metabolic mechanisms and synergistic roles of biothiols under hypoxia, this study provides evidences for physiological status assessment, early diagnosis and regulation of hypoxia-related disorders.