A simple, inexpensive, and portable lateral flow assay platform that uses platinum nanoparticles to amplify signals and achieve single-molecule sensitivity.

Point-of-care (POC) diagnostics are able to provide rapid on-site results in non laboratory settings and play a key role in public health for rural and under-developed areas of the world. However, most traditional POC platforms are limited by low sensitivity and lack of quantification, and therefore cannot meet certain clinical needs. Traditional diagnostics often require expensive equipment, complex imaging, or laboratory expertise to operate, and therefore, cannot be used in low-resource settings.

This technology is a simple, inexpensive, ultra-sensitive, and portable platinum nanoparticle-initiated bubbling digital assay (PNDA) platform for POC tests. A microfluidic array is decorated with antibodies for the target biomarker in close proximity to platinum nanoparticles, which catalyze the generation of oxygen microbubbles. The digital assay platform uses this “express bubbling” to transform and amplify the signal, thus enabling the detection of single molecules.

A widely available handheld microscope (or smart phone accessory) can be used to perform a readout from the PNDA Chip. The PNDA technology can be incorporated into a lateral flow assay (LFA) to provide a quantitative distance-based test readout. The entire immunoassay process can be integrated on to the LFA to process a single drop of sample in one step.

• Low cost through the use of common reagents
• One-step, simple assay procedure
• Can be used in non-laboratory environments
• High sensitivity (single-molecule level)
• Complex imaging and fluorescence are not required
• Quantitative output

• Point-of-care and portable health diagnostics
• Single-molecule detection
• Chemical tests in non-laboratory settings