Lateral Flow Assay: A Summary of Recent Progress for Improving Assay Performance

Abstract

Lateral flow tests are one of the most important types of paper-based point-of-care (POCT) diagnostic tools. It shows great potential as an implement for improving the rapid screening and management of infections in global pandemics or other potential health disorders by using minimally expert staff in locations where no sophisticated laboratory services are accessible. They can detect different types of biomarkers in various biological samples and provide the results in a little time at a low price. An important challenge regarding conventional LFAs is increasing their sensitivity and specificity. There are two main approaches to increase sensitivity and specificity, including assay improvement and target enrichment. Assay improvement comprises the assay optimization and signal amplification techniques. In this study, a summarize of various sensitivity and specificity enhancement strategies with an objective evaluation are presented, such as detection element immobilization, capillary flow rate adjusting, label evolution, sample extraction and enrichment, etc. and also the key findings in improving the LFA performance and solving their limitations are discussed along with numerous examples.

Development of an Antigen Capture Lateral Flow Immunoassay for the Detection of Burkholderia pseudomallei

“…The assay construction was performed using materials and buffers that are commonly used or made by local manufacturers in the country to avoid disruption in the event that scaling-up is needed. During the optimization, we decided to primarily focus on the nitrocellulose membrane and chase buffer, the two major components that usually affect the test accuracy [30,31]. The other components of the LFIAs were selected based on the previous study and were kept unchanged throughout the optimization [25].…”

Lateral Flow Assay Biotesting by Utilizing Plasmonic Nanoparticles Made of Inexpensive Metals─Replacing Colloidal Gold

“…We should also comment on other inexpensive materials for LFAs, such as latex, polystyrene, carbon, quantum dots, magnetic NPs, and upconversion NPs, among others. − However, several of these LFAs require sophisticated equipment for reading out the results, hence delaying a possible diagnosis. − Additionally, these materials do not show the benefits of plasmonic systems, such as propagating/localized surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS), fluorescence and infrared absorption spectroscopy, among others, broadening the possible applications in which our NPs could be used. For example, our functionalized NPs could perform similarly to the Au NPs used in a recent study that built a plasmonic resonator for obtaining femtomolar detection levels of (SARS)-CoV-2 …”

Measuring the performance of computer vision artificial intelligence to interpret images of HIV self-testing results

“…Compared to images of HIV RDTs performed by trained healthcare providers or activated by trained lab technicians using human blood samples, images of HIVSTs conducted by real-world clients on themselves might vary in ways that could affect AI algorithm performance. For example, inexperienced self-testers might apply smaller amounts of the blood sample to the test strip, making test lines harder to detect ( 35 ). We, therefore, sought to evaluate the performance of an AI algorithm at interpreting images of HIVSTs collected during routine service delivery at private, community-based pharmacies in Kenya.…”