Single-Line Flow Assay Platform Based on Orthogonal Emissive Upconversion Nanoparticles.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Lateral flow assays (LFAs) are crucial for rapid diagnostics but face limitations in high-throughput quantitative analysis due to their double-line design.
• The restricted sample diffusion distance in traditional LFAs limits the number of test and control lines, hindering scalability.

Purpose of the Study:

• To develop a novel single-line-based LFA (sLFA) that integrates test and control functionalities.
• To enhance the throughput, accuracy, and cost-effectiveness of LFAs for diverse applications.

Main Methods:

• Utilized orthogonal emissive upconversion nanoparticles (UCNPs) as signal reporters on a single test line.
• Designed a UCNP-based test line with an internal reference, serving dual reporting and calibrating roles.
• Demonstrated the sLFA's capability by detecting aflatoxin B1 in a proof-of-concept study.

Main Results:

• Successfully developed and validated a single-line LFA (sLFA) strip.
• The UCNP-based test line provided both reporting and calibrating signals, eliminating the need for separate control lines.
• Achieved accurate and rapid detection of aflatoxin B1, showcasing the assay's potential.
• Reduced strip size and fabrication costs by eliminating control lines.

Conclusions:

• The novel sLFA strategy significantly improves detection capacity and accuracy while reducing costs.
• This single-line design facilitates the development of compact testing arrays for multiplexed detection.
• The sLFA holds promise for advancing applications in food analysis and in vitro diagnostics.