Rapid Viral Diagnostic Test by Digital Plasmonic Nanobubbles

Project Summary/Abstract: Respiratory viruses are among the most serious threats to global public health, in part due to the limitations of currently commercially available tests: the high cost and time-consuming nature of lab-based tests, as well as the comparatively lower sensitivity and specificity of point-of-care (PoC) tests. There is a significant need for a rapid, portable, and inexpensive testing capability that is both highly sensitive and specific. The broad, long-term objective of this project is the development of a highly sensitive viral diagnostic test employing Avsana Labs’ digital plasmonic nanobubble (digital PNB) counting technology for detection of RSV, a globally significant virus selected for proof-of-concept studies. The viral test device implements sensing of virus particles by means of their attachment to antibody-conjugated gold nanoparticles, employing laser beams co-aligned in an optical fiber to generate nanobubbles from gold nanoparticles in a digital format (presence or absence of large nanobubbles) with the use of a microfluidic chip. The test will feature a rapid test turnaround time, high sensitivity and specificity, low cost, portability, and ease of use that will make it suitable for the PoC, including low-resource settings. Aim 1: Develop alpha-prototype platform for dPNB assay, demonstrating portability and functionality. In a related R01 study, the assay is realized using a laboratory setup. This aim will focus on miniaturizing optics and electronics from the lab setup into a benchtop-portable device as an alpha- prototype of a PoC platform, which would incorporate all the necessary signal processing around the detection mechanism, enabling a low-cost self-contained solution. Aim 2: Optimize the assay workflow and chemistry for intact RSV virus detection in clinical specimen matrix. The goal is to establish a robust assay workflow and chemistry to detect intact viruses in de-identified nasopharyngeal swab samples, in order to integrate with the alpha-prototype from Aim 1 and advance the technology toward a reliable diagnostic test for use in the clinic. Aim 3: Test the sensitivity and specificity of the dPNB assay with a pilot cohort of de-identified clinical containing RSV and Influenza type A specimens using the alpha-prototype. An important milestone towards commercialization is to establish early-on the ability to detect viruses in clinical specimens. We will test a small cohort of 60 de-identified clinical specimens, and use the original laboratory setup for reference. Societal benefits and broader impact on public health will be found in rapid and accurate in vitro viral pathogen diagnosis. Avsana envisions that the PNB platform will benefit the management of seasonal respiratory and emerging viral infections, and that additionally, it will accelerate the pandemic response and reduce the loss of lives in the likely event of future viral pandemics.