High-performance photoelectrochemical immunosensor based on featured photocathode-photoanode operating system

Area of Science:

• Photoelectrochemical (PEC) sensing
• Immunosensor technology
• Nanomaterial-based biosensing

Background:

• Photocathodic immunosensors offer superior anti-interference but suffer from weak photocurrent signals.
• Photoanodic immunosensors have stronger signals but limited anti-interference capabilities.
• Integrating both photocathode and photoanode functions in a single system is crucial for high-performance biosensing.

Purpose of the Study:

• To develop an efficient and feasible photoelectrochemical (PEC) immunosensor by integrating photocathode and photoanode functionalities.
• To enhance detection performance by overcoming the weak photocurrent limitations of traditional photocathodic immunosensors.
• To demonstrate the sensor's capability for sensitive and specific detection of alpha-fetoprotein (AFP) as a model antigen.

Main Methods:

• Fabrication of a TiO2/AgInS2 quantum dot (AIS QD) photoanode and a carbon nanotube/CuInS2 nanoflower (CNT/CIS NF) photocathode.
• Immobilization of anti-AFP antibody (Ab) on the CNT/CIS photocathode for immune recognition.
• Detection of AFP antigen (Ag) based on the decrease in photocurrent signal due to steric hindrance upon binding.
• Utilizing a photocathode-photoanode operating system for signal amplification and anti-interference.

Main Results:

• The integrated PEC immunosensor demonstrated sensitive and specific detection of AFP.
• The sensor design effectively leveraged the combined properties of the photocathode and photoanode.
• A significant decrease in photocurrent signal correlated with the amount of captured AFP antigen.
• The system exhibited enhanced anti-interference abilities suitable for biological specimen analysis.

Conclusions:

• The developed photocathode-photoanode integrating strategy offers a promising approach for high-performance PEC immunosensors.
• This novel design overcomes the limitations of individual photocathodic and photoanodic systems.
• The sensor provides a sensitive and specific platform for detecting biomarkers in complex biological matrices.