High Selectivity Fluorescence and Electrochemical Dual-Mode Detection of Glutathione in the Serum of Parkinson’s Disease Model Mice and Humans
Hui Dong, Weitian Chen, Ke Xu, Linlin Zheng, Bingyu Wei, Ruiyu Liu, Jingru Yang, Tao Wang, Yanli Zhou, Yintang Zhang, Maotian Xu
Abstract
Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons and the accumulation of alpha-synuclein. Glutathione (GSH), a key antioxidant, is significantly depleted in PD patients. This study presents a dual-mode detection strategy for selectively determining GSH using a single probe. A series of “turn-on” electrochemical and fluorescent probes were developed, with resorufin (Re) serving as the reporting unit and featuring specific GSH recognition sites. Among these, the 7-(3,5-dinitrophenoxy)-3 H -phenoxazin-3-one (Re-DNP) probe was selected for its high selectivity as both a fluorescent and electrochemical probe. Its response to GSH was superior in comparison to that observed for hydrogen sulfide (H 2 S) and cysteine (Cys). For electrochemical detection using screen-printed carbon electrode (SPCE)/carbon nanotube (CNT) modified electrodes, the detection limit for GSH was 5 μM, with a linear range of 25–500 μM. In fluorescence detection, the probe produced a 78-fold increase in emission at 630 nm in the presence of GSH, with a strong linear correlation between fluorescence intensity and GSH concentration in the range of 10–700 μM, and a detection limit of 2 μM. When applied to real clinical serum samples, the probe demonstrated significantly lower GSH levels in both PD mice and human patients compared to healthy controls. This dual-mode detection method provides a sensitive and accurate tool for GSH detection, with potential applications in understanding GSH’s role in PD and related neurodegenerative diseases.