Sensitive Affinity-Based Biosensor Using the Autocatalytic Activation of Trypsinogen Mutant by Trypsin with Low...

Area of Science:

• Biochemistry
• Biosensor Technology
• Analytical Chemistry

Background:

• Protease-based autocatalytic reactions offer high signal amplification for biosensors.
• Limited availability of fast autocatalytic protease reactions and proenzyme self-activation hinder their application.
• Prostate-specific antigen (PSA) is a key biomarker for prostate cancer detection.

Purpose of the Study:

• To develop a highly sensitive biosensor for PSA detection using a self-propagating autocatalytic protease reaction.
• To overcome limitations of proenzyme self-activation and enhance signal amplification.
• To achieve a low detection limit for PSA using a novel autocatalytic approach.

Main Methods:

• A sandwich-type immunosensor was designed utilizing a trypsinogen mutant and trypsin as a catalytic label.
• Autocatalytic activation of the trypsinogen mutant by trypsin generated a cascade amplification.
• Electrochemical detection of liberated 4-aminophenol (AP) via redox cycling at a modified ITO electrode.

Main Results:

• The novel biosensor achieved a low detection limit of approximately 7 pg/mL for PSA.
• The autocatalytic activation strategy significantly reduced background noise and enhanced signal amplification.
• Compared to using trypsin alone (∼100 pg/mL), the autocatalytic method showed a substantial improvement in sensitivity.

Conclusions:

• Autocatalytic activation of proenzymes is a powerful strategy for signal amplification in biosensors.
• The developed biosensor demonstrates high sensitivity and low detection limits for PSA.
• This approach holds promise for sensitive and reliable biomarker detection in clinical diagnostics.