Optimization of hydrogen peroxide detection for a methyl mercaptan biosensor.

Area of Science:

• Electrochemistry
• Biosensor Development
• Analytical Chemistry

Background:

• Carbon screen-printed electrodes (CSPEs) are versatile platforms for electrochemical sensing.
• Hydrogen peroxide (H₂O₂) is a key analyte in various biological and environmental processes.
• Methyl mercaptan (MM) detection requires sensitive and selective biosensing strategies.

Purpose of the Study:

• To fabricate and evaluate various modified CSPEs for sensitive H₂O₂ detection.
• To identify the optimal electrode modification for establishing a methyl mercaptan (MM) biosensor.
• To determine the limit of detection (LOD) for H₂O₂ using different CSPE modifications.

Main Methods:

• Fabrication of modified CSPEs including carbon nanotubes (CNTs), cobalt phthalocyanine (CoPC), Prussian blue (PB), and Os-wired HRP.
• Amperometric detection of H₂O₂ at specific applied potentials versus Ag/AgCl.
• Calculation of the limit of detection (LOD) for H₂O₂ for each modified electrode.

Main Results:

• Os-wired HRP modified CSPEs exhibited the lowest LOD for H₂O₂ (13.7 nM) at a low working potential (-0.1 V).
• Compared to unmodified CSPEs, all modified electrodes showed improved H₂O₂ detection limits.
• The Os-wired HRP modification proved most effective for H₂O₂ sensing.

Conclusions:

• Os-wired HRP modified CSPEs are highly suitable for sensitive H₂O₂ detection.
• This optimal electrode modification facilitates the development of a methyl mercaptan (MM) biosensor with a 0.5 μM detection limit.
• The study highlights the potential of advanced electrode materials in enhancing biosensor performance.