Band Alignment Modulated Polarity-Switchable PEC Ratiometric Sensor through Coupling a pH-Responsive CuTCPP MOF with...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Conventional ratiometric photoelectrochemical (PEC) sensors utilize dual independent photosensitive materials, leading to interface modification inconsistencies.
• This
• two-to-two
• mode often results in questionable signal reliability and detection accuracy.

Purpose of the Study:

• To develop a novel
• one-to-two
• ratiometric PEC sensor employing a single electrode interface.
• To address the limitations of dual-interface modification in conventional ratiometric PEC sensors.

Main Methods:

• Engineered pH-modulated band alignment on a single CuTCPP/WS₂ photoelectric substrate.
• Utilized an i-motif sensing tool to generate dual ratiometric signals (photoanodic and photocathodic) via synergistic action.
• Formed a ternary heterostructure with CdS QDs for detection signal under alkaline conditions and observed polarity conversion under acidic conditions.

Main Results:

• Achieved accurate and reliable ratio detection of mycotoxin ochratoxin A.
• Demonstrated a novel two-wing signal generation strategy with pH-modulated band alignment engineering.
• Validated the feasibility of the
• one-to-two
• ratiometric PEC sensor for practical analysis.

Conclusions:

• This work provides a new design strategy for PEC ratiometric determination systems.
• The developed sensor offers improved accuracy and reliability compared to conventional methods.
• Highlights the potential of pH-modulated band alignment engineering in sensor development.