Two-Dimensional MoS<sub>2</sub>-Based Electrochemical Biosensor for Highly Selective Detection of Glutathione
Brajesh Rawat, Kundan Kumar Mishra, Ujjwol Barman, Leena Arora, Durba Pal, Roy Paily
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 MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> 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 fabrication technologies for large scale production.Therefore, this work develops an electrochemical sensor based on MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> 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 MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> surface, and the electrochemical activity of GSH and 1-chloro-2,4-dinitrobenzene(CDNB) in the presence of GST was utilized for GSH detection. MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based sensor was showed a high selectivity of 535 × larger current compared to a blank test. The electrochemical sensor 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 MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based sensor exhibited the excellent repeatability and stability that makes its novel sensing device for cancer detection and quantification.