Ultra-sensitive fiber optic LSPR biosensor with enhanced enzyme functionalization for real-time putrescine detection

Area of Science:

• Analytical Chemistry
• Biosensing Technology
• Food Safety Science

Background:

• Putrescine is a biogenic amine associated with food deterioration and safety concerns.
• Accurate detection of putrescine is crucial for quality control in the food industry.
• Existing detection methods may lack the sensitivity or speed required for real-time monitoring.

Purpose of the Study:

• To develop and validate a novel fiber optic biosensor for sensitive and selective putrescine detection.
• To enhance sensor performance using advanced nanomaterials and surface functionalization.
• To evaluate the biosensor's applicability in real-world food sample analysis.

Main Methods:

• Fabrication of an S-tapered fiber optic probe with a waist extension.
• Immobilization of gold nanoparticles (AuNPs) to induce localized surface plasmon resonance (LSPR).
• Integration of multi-walled carbon nanotubes (MWCNTs) and niobium carbide (Nb2CTx) for increased enzyme binding.
• Functionalization of the probe surface with diamine oxidase (DAO) for specific putrescine recognition.

Main Results:

• The biosensor demonstrated a sensitivity of 2.04 nm/lg(µM) and a limit of detection of 0.267 µM.
• A linear detection range of 0-100 µM was established for putrescine.
• The sensor exhibited good repeatability, reusability, selectivity, and performance across different pH values and in real food samples.

Conclusions:

• The developed fiber optic biosensor shows significant potential for accurate and reliable putrescine quantification.
• The combination of LSPR, nanomaterials, and enzymatic functionalization enhances biosensing performance.
• This technology offers a promising tool for advancing food quality and safety assessment.