Exogenous coreactant-free integrated ECL biosensor based on P5AIn/Fe(II)-MOF for sensitive trimethylamine N-oxide...

Area of Science:

• Electrochemistry
• Biosensing
• Materials Science

Background:

• Trimethylamine N-oxide (TMAO) is a key indicator of seafood freshness.
• Existing methods for TMAO detection often lack integration and sensitivity.
• Developing rapid, sensitive, and integrated TMAO detection is crucial for food safety.

Purpose of the Study:

• To develop a novel, exogenous coreactant-free integrated ECL immunosensor for sensitive TMAO detection.
• To utilize a dual-functional platform of poly(5-aminoindole)/Iron-based metal-organic framework (P5AIn/Fe-MOF).
• To simplify operational procedures for TMAO analysis.

Main Methods:

• Constructed an integrated ECL immunosensor using P5AIn/Fe-MOF composite.
• Employed Fe-MOF as a co-reaction promoter and reduction matrix for TMAO conversion.
• Designed an ECL probe with Ru(bpy)₃²⁺ loaded onto Zn₃(HHTP)₂ and conjugated with antibodies.
• Integrated sample pretreatment and signal generation into a single platform.

Main Results:

• The P5AIn/Fe-MOF platform demonstrated synergistic effects, enhancing electron transfer and catalytic accessibility.
• Generated trimethylamine (TMA) acted as an endogenous coreactant, amplifying ECL signals.
• The Zn₃(HHTP)₂ confined Ru(bpy)₃²⁺, boosting the ECL response.
• Achieved a wide linear range (0.1-100 ng/mL) and a low detection limit (0.033 ng/mL).
• Successfully applied the biosensor to detect TMAO in frozen shrimp samples.

Conclusions:

• The study presents a novel exogenous coreactant-free detection strategy for TMAO.
• The integrated platform offers a simple, rapid, and sensitive approach for TMAO detection.
• This method shows promising applications in marine food safety monitoring.