Two-dimensional MoS2-based electrochemical biosensor for highly selective detection of glutathione

Abstract

Glutathione (GSH) recently emerges as an important biomarker for cancers and various disease detection as its concentration varies in the µM to mM range in biological cells and fluids. Despite extensive efforts devoted to optical detection and quantification of GSH, there still exits an intensive demand for the development of an electrochemical sensor to allow rapid measurements even in lower concentration limit with excellent repeatability and accuracy. Two-dimensional MoS2 can be a promising candidate to enhance biosensor performance as it offers a larger surface-to-volume ratio, suitable bandgap, label-free sensing capability, and compatibility with commercial planner fabricationtechnologiesfor large scale production.Therefore, this work develops an electrochemical sensor based on MoS2 for the detection and quantification of GSH concentration to investigate the perspective of biopsy-free cancer detection. The Glutathione-S-Transferase (GST) was immobilized on the MoS2 surface, and the electrochemical activity of GSH and 1-chloro-2,4-dinitrobenzene (CDNB) in the presence of GST was utilized for GSH detection. MoS2-based sensor was showed a high selectivity of 535 × larger current compared to a blank test. The electrochemicalsensor has exhibited the sensitivity of 704 pA/µM and the limit of detection of 703 nM with a wider linear detection range of 10 µM - 500 mM. Furthermore, the MoS2-based sensor exhibited the excellent repeatability and stability that makes its novel sensing device for cancer detection and quantification.