Integrating Surface Enhanced Raman Spectroscopy Nanomaterials into Lateral Flow Assay for Oral Health Diagnostics

In fifteen words or less, explain the significance of this contribution (Novel Aspect).: Improve the sensitivity and quantification of lateral flow assay detection of gingivitis using saliva

Abstract Text: The use of point-of-care (POC) detection increased dramatically during and after the COVID-19 pandemic. The lateral flow assay (LFA) test is presently one of the most widely used rapid diagnostic tests usually performed in a POC diagnostics setting. Compared to lab-based quantitative methods of detection, such as polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), LFA tests are much faster and cheaper and do not require technical operators. However, LFAs have limited sensitivity and a binary (i.e., yes/no) output, which makes quantification of, for example, viral load challenging. Surface enhanced Raman spectroscopy (SERS) has been proposed to improve the LFA detection sensitivity. Specifically, our group has tested the use of different type of nanomaterials in SERS+LFA, including gold nanoparticles (AuNPs) and silver-coated gold nanostar (Ag@AuNS). Our current work focuses on expanding the use of this SERS+LFA system targeting oral health diagnostic to improve the detection of Porphyromonas gingivalis (
P. gingivalis

), which is bacteria in the oral cavity. We observed significant interference between saliva and the SERS nanoparticles used in the LFA. In this work, we explored and addressed saliva-related interference in SERS-LFA detection by using a refine pretreatment approach utilizing starch to decrease amylase levels, which was discovered to be the cause of interference, without compromising LPS detection. Using this approach significant LOD improvements were obtained for the SERS LFA analysis: 0.017 ng/mL and 0.080 ng/mL for Ag@AuNS and AuNPs, respectively. Future steps will involve taking full advantage of the SERS+LFA platform, demonstrating long-range quantification of target analytes.