Development of a Photoelectrochemical Microelectrode Using an Organic Probe for Monitoring Hydrogen Sulfide in Living Brains

Yuanqiang Hao; Yewen Yang; Wenhui Wang; Hui Gu; Wansong Chen; Chunlan Li; Peisheng Zhang; Rongjin Zeng; Maotian Xu; Shu Chen

doi:10.1021/acs.analchem.4c05336

Development of a Photoelectrochemical Microelectrode Using an Organic Probe for Monitoring Hydrogen Sulfide in Living Brains

Anal Chem. 2024 Nov 22. doi: 10.1021/acs.analchem.4c05336. Online ahead of print.

Authors

Affiliations

¹ Key Laboratory of Theoretical Organic Chemistry and Functional Molecule, Ministry of Education, Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.
² Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, China.
³ Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Henan Joint International Research Laboratory of Chemo/Biosensing and Early Diagnosis of Major Diseases, Shangqiu Normal University, Shangqiu, Henan Province 476000, China.

PMID: 39576966
DOI: 10.1021/acs.analchem.4c05336

Abstract

Hydrogen sulfide (H₂S) is an important bioactive molecule that plays a significant role in various functions, particularly in the living brain, where it is closely linked to cognition, memory, and several neurological diseases. Consequently, developing effective detection methods for H₂S is essential for studying brain functions and the underlying mechanisms of these diseases. This study aims to construct a novel photoelectrochemical (PEC) microelectrode Ti/TiO₂@HSP for the quantitative monitoring of H₂S levels in the living brain. The PEC microelectrode Ti/TiO₂@HSP is formed by covalently bonding a specifically designed organic PEC probe HSP, which possesses a D-π-A structure, to the surface of TiO₂ nanotubes generated via in situ anodic oxidation of titanium wire. The PEC probe HSP can effectively react with H₂S and generate significant photocurrent response under long-wavelength excitation light (560 nm), thereby achieving quantitative detection of H₂S. The sensor demonstrates high sensitivity and good selectivity. In vivo experiments utilizing the PEC microelectrode Ti/TiO₂@HSP enable the monitoring of dynamic changes in H₂S levels across various regions of the mouse brain. The findings reveal that in normal mice, the concentration of H₂S in the hippocampus is significantly higher than in the striatum and cerebral cortex. Additionally, following propargylglycine drug stimulation, H₂S concentrations in different brain regions were observed to decrease, with the most substantial reduction noted in the hippocampus. This suggests that cystathionine γ-lyase (CSE) is the primary enzyme responsible for H₂S production in this area, while the striatum exhibits a less pronounced decrease in H₂S concentration, indicating a reliance on alternative enzymatic pathways for H₂S production. Therefore, this study not only successfully develops a high-performance H₂S detection sensor but also provides new experimental tools and theoretical foundations for further exploring the roles of H₂S in neurophysiological and pathological processes.