High-Sensitive Hydrogel Optofluidic Microcavities for Heavy Metal Ion Detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Hydrogels show potential for heavy metal ion detection in fluids.
• Detecting multiple analytes in complex matrices like Chinese herbs is challenging due to subtle signals.

Purpose of the Study:

• To develop a hydrogel optofluidic sensor for amplifying analyte signals.
• To enable sensitive and selective detection of heavy metal ions (Pb²⁺, Hg²⁺) in complex solutions.

Main Methods:

• Integration of a hydrogel film within a whispering-gallery-mode (WGM) microcavity.
• Utilizing the red shift of WGM resonance spectra to quantify heavy metal ion concentrations.
• Modification of hydrogels with aptamers for enhanced sensitivity and selectivity.

Main Results:

• The hydrogel microcavity sensor effectively detected heavy metal ions by inducing WGM resonance shifts.
• Aptamer modification led to high sensitivity and selectivity in ion detection.
• The platform demonstrated practical applicability in analyzing Chinese herbs for Pb²⁺ content.

Conclusions:

• The developed hydrogel optofluidic sensor offers a promising approach for sensitive heavy metal ion monitoring.
• This technology has potential applications in functional hydrogel sensors and healthcare diagnostics.
• The study highlights the utility of light-matter interactions for signal amplification in complex sample analysis.