Photothermal Microfluidic Sensing Platform Using Near-Infrared Laser-Driven Multiplexed Dual-Mode Visual Quantitative...

Area of Science:

• Microfluidics
• Analytical Chemistry
• Materials Science

Background:

• Microfluidic devices offer potential for point-of-care testing (POCT).
• Integrating diverse sensing principles enhances microfluidic device capabilities.
• Photothermal sensing is explored for advanced analytical applications.

Purpose of the Study:

• To develop a photothermal microfluidic sensing platform using microfluidic paper-based analytical devices (μPADs).
• To achieve multiplexed, dual-mode visual quantitative readout for analyte detection.
• To utilize Prussian blue (PB) as an on-chip photothermal sensing element.

Main Methods:

• In situ synthesis of Prussian blue (PB) within thermoresponsive poly(N-isopropylacrylamide) hydrogels.
• Utilizing near-infrared (NIR) laser to drive photothermal effects for sensing.
• Implementing dual-mode readout based on thermal imaging and dye release distance.
• Demonstrating proof-of-concept detection of silver ions in environmental water.

Main Results:

• The photothermal effect of PB generated dose-dependent heat and triggered dye release.
• Both temperature elevation and dye travel distance correlated with analyte concentration.
• The developed μPAD detected silver ions down to 0.25 μM with high selectivity and accuracy.
• The platform demonstrated multiplexed, dual-mode visual quantitative readout.

Conclusions:

• The photothermal microfluidic sensing platform shows significant promise for POCT applications.
• The integration of photothermal sensing, μPADs, and responsive hydrogels offers broad applicability.
• The platform's design facilitates easy integration and potential for diverse analyte detection.