A Diffusion-Driven Chromogenic Reagent-Free Viscosity-Based Sensor with Dual Signals for the Visual Detection of...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Point-of-care testing (POCT) demands simple, affordable, and reliable methods.
• Existing methods for detecting enzymes like hyaluronidase (HAase) can be complex or require specialized equipment.

Purpose of the Study:

• To develop a dual-mode viscosity-based sensor (DM vis-sensor) for rapid, visual, and instrument-free detection of hyaluronidase (HAase).
• To leverage diffusion-driven viscosity changes on a mesoporous membrane for enzyme detection.

Main Methods:

• Utilized enzymatic cleavage of hyaluronic acid (HA) by HAase, which decreases viscosity.
• Developed a sensor exploiting altered diffusion patterns (spot size and color/grayscale ratio) on a mesoporous membrane.
• Implemented dual-readout detection based on diffusion spot diameter and grayscale ratio (GR).

Main Results:

• Demonstrated visual and instrument-free detection of HAase based on viscosity reduction.
• Achieved high sensitivity with detection limits of 0.12 U/mL (distance) and 0.16 U/mL (grayscale).
• Successfully validated the sensor for HAase quantification in human urine samples.

Conclusions:

• The developed DM vis-sensor provides a simple, low-cost, and reliable POCT tool.
• Its dual-readout capability enhances diagnostic accuracy and practicality.
• The sensor shows significant potential for early disease diagnosis and monitoring, particularly in resource-limited settings.