Microfluidic sensor using pH gradient with hybrid magnetoliposomes containing laccase immobilized nanocrystals

Area of Science:

• Biochemistry and Analytical Chemistry
• Nanotechnology and Materials Science
• Microfluidics and Biosensing

Background:

• Enzyme-based detection methods require efficient enzyme delivery and retention.
• Magnetoliposomes offer a controlled system for encapsulating and localizing enzymes.
• Microfluidic systems enable high-throughput and sensitive analytical assays.

Purpose of the Study:

• To develop a pH-sensitive microfluidic system for enzyme-based detection.
• To utilize hybrid magnetoliposomes for enzyme immobilization and preconcentration.
• To quantify laccase inhibitors in food and beverage samples.

Main Methods:

• Hybrid magnetoliposomes encapsulating laccase immobilized on PAA-MNCs were used.
• A pH gradient triggered phospholipid dissociation for enzyme release control.
• Laccase-mediated oxidation of HPTS served as the indicator reaction.
• The system was integrated into a microfluidic device for analysis.

Main Results:

• The method achieved high sensitivity with detection limits between 6-30 nmol L⁻¹.
• Dynamic ranges for inhibitors (cysteine, malic, fumaric acid) were up to 100 μmol L⁻¹.
• Precision (RSD%) ranged from 2.5-5.1%, with a sampling frequency of 8 h⁻¹.
• Fumaric acid in juices was quantified with 85-101% recovery, comparable to LC methods.

Conclusions:

• The developed microfluidic system effectively uses pH-triggered magnetoliposomes for sensitive enzyme-based detection.
• The method allows for the determination of laccase inhibitors in real samples with high accuracy.
• This approach offers a promising platform for rapid and sensitive biochemical analysis.