Photothermal sensing via DNAzyme catalysis for MicroRNA detection at the point-of-care

Area of Science:

• Biomedical Engineering
• Molecular Diagnostics
• Nanotechnology

Background:

• MicroRNA (miRNA) detection is crucial for diagnostics and prognostics.
• Current miRNA detection methods are often expensive and require specialized expertise.
• There is a need for simple, accessible, and sensitive miRNA detection technologies.

Purpose of the Study:

• To develop a nonenzymatic, isothermal amplification-based photothermal nucleic acid sensor for miRNA detection.
• To create a switchable photothermal platform that converts miRNA signals into measurable temperature changes.
• To enable visual interpretation of results for point-of-care applications.

Main Methods:

• Engineered DNA circuit switches activating light-to-heat converters via allosteric DNAzyme.
• In situ activation of photothermal materials through a cascade reaction.
• Utilizing autonomously assembled DNAzyme for catalyzing reporter oxidation and thermoplasmonic activation.
• Measurement with handheld devices for temperature and colorimetric read-outs.

Main Results:

• The platform demonstrated sensitive conversion of miRNA signals into elevated local temperatures.
• DNAzyme catalyzed oxidation of photoagent precursors and thermoplasmonic activation of nanostructures.
• Robust response observed in complex biofluids and resilience to ambient temperature fluctuations.
• Visually interpretable temperature output achieved.

Conclusions:

• The photothermal biosensing approach offers high sensitivity, simplicity, and robustness for miRNA detection.
• This method eliminates the need for expensive equipment, reagents, and complex labeling.
• The technology holds potential for point-of-care testing (POCT), particularly in resource-limited areas.