A photoelectrochemical sensing strategy based on single-layer MoS₂ modified electrode for methionine detection

Area of Science:

• Materials Science
• Electrochemistry
• Analytical Chemistry

Background:

• Molybdenum disulfide (MoS2) is a common material in photoelectrochemical (PEC) sensors, typically operating via "signal-on" strategies.
• Methionine detection is crucial in various biological and clinical applications.

Purpose of the Study:

• To develop a novel "signal-off" PEC sensing strategy for methionine detection using MoS2.
• To investigate the quenching effect of methionine on MoS2-based PEC responses.
• To optimize experimental conditions for sensitive and selective methionine quantification.

Main Methods:

• Fabrication of a MoS2-modified electrode.
• Investigation of PEC response under varying experimental conditions (bias potential, MoS2 volume, pH).
• Quantitative analysis of methionine using the developed PEC sensor.

Main Results:

• A "signal-off" PEC sensing strategy for methionine was successfully developed for the first time.
• The PEC response of MoS2 was significantly quenched by methionine.
• Optimized conditions yielded a linear logarithmic response to methionine concentrations from 0.1 nM to 1 μM, with a detection limit of 0.03 nM.
• The method demonstrated excellent selectivity and potential for real-sample analysis.

Conclusions:

• The developed MoS2-based PEC sensor provides a simple, rapid, selective, and highly sensitive method for methionine detection.
• This work expands the application scope of PEC detection strategies.
• The sensor shows promise for practical applications in determining methionine in real-life samples.