A portable and universal upconversion nanoparticle-based lateral flow assay platform for point-of-care testing

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Upconversion nanoparticle-based lateral flow assays (UCNP-LFAs) are valuable for point-of-care testing (POCT) due to photostability and high signal-to-noise ratio.
• Existing UCNP-LFAs often rely on bulky, expensive peripheral equipment for signal excitation and readout.
• There is a need for miniaturized, portable, and cost-effective UCNP-LFA systems for broader POCT applications.

Purpose of the Study:

• To develop a miniaturized and portable UCNP-LFA platform for enhanced POCT.
• To integrate a lateral flow assay (LFA) detection system, a dedicated reader, and a smartphone-based analyzer.
• To demonstrate the platform's capability for sensitive and quantitative multiplexed detection of diverse targets.

Main Methods:

• Developed a UCNP-LFA platform comprising an LFA detection system utilizing three types of UCNPs for multiplexed detection.
• Designed a compact reader (24.0 cm × 9.4 cm × 5.4 cm, 0.9 kg) for fluorescence signal excitation and readout.
• Integrated a smartphone with custom software as a UCNP-LFA analyzer for real-time quantitative analysis.

Main Results:

• The platform achieved highly sensitive and quantitative detection of various targets: ochratoxin A (small molecule), Hg²⁺ (heavy metal ion), Salmonella (bacteria), HBV (nucleic acid), and ST-2 (protein).
• Demonstrated the universality and robustness of the developed UCNP-LFA platform across different analyte types.
• The smartphone-assisted analyzer provided real-time quantitative results, showcasing the system's efficiency.

Conclusions:

• The developed miniaturized and portable UCNP-LFA platform offers a promising solution for POCT.
• This technology enables sensitive, quantitative, and multiplexed detection of diverse analytes.
• The platform has significant potential for applications in disease diagnostics, environmental monitoring, and food safety.