MT-I/AuNP-Based Fiber-Optic SPR Biosensor for Ultralow Limit Triglyceride Detection and On-Site Hydrolysis

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Biochemistry

Background:

• Triglyceride (TG) is a key biomarker in lipid metabolism, crucial for health management.
• Accurate, trace-level detection and understanding of TG hydrolytic processes are essential.
• Existing detection methods often lack the sensitivity and on-site capabilities required.

Purpose of the Study:

• To develop a novel biosensor for rapid and ultrasensitive detection of triglycerides (TG).
• To enable on-site hydrolysis of TG using an integrated enzymatic approach.
• To create a synergistic sensing system combining protein-nanoparticle-enzyme functionalities.

Main Methods:

• Functionalization of a tilted fiber Bragg grating (TFBG) with a composite layer: Au-MT-I/AuNPs/lipase.
• Utilizing Au-S bond self-assembly for thiol group immobilization of metallothionein-I (MT-I).
• Employing EDC/NHS chemistry for covalent linkage of AuNPs-NH2 and lipase via amide bonds.

Main Results:

• Achieved ultrasensitive TG detection with a sensitivity of 0.346 dB/lg(mM) and a low limit of detection (LOD) of 4.192 μM.
• Demonstrated on-site hydrolysis of TG into glycerol and free fatty acids catalyzed by immobilized lipase.
• The sensor surpassed previous detection limits by over 4 orders of magnitude.

Conclusions:

• The developed dual-functional biosensor offers a novel platform for TG detection and enzymatic reaction monitoring.
• The "protein-nanoparticle-enzyme" synergistic system provides a valuable reference for future biosensor design.
• This approach enables rapid response and ultrasensitive detection, crucial for human health management.