Nanomaterial-Based Optical Biosensors for SARS-CoV-2 Detection: A Retrospective of the Pandemic

Abstract

From 2020 to 2023, the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global health crisis, as millions of people worldwide contracted the coronavirus disease of 2019 (COVID-19). Conventional diagnostic techniques, such as reverse transcription-quantitative polymerase chain reaction (RT-PCR), struggled to meet increasing testing needs required for a pandemic owing to significant downsides hindering their large-scale use. In efforts to curb the effects of the pandemic and to meet the increasing demand for fast and accurate point-of-care (POC) testing, scientists and industries alike raced to engineer new diagnosis methods and adapt previously developed ones. Now that the COVID-19 pandemic has passed, the present review aims to provide the reader with an overview of recent advances in biosensing resulting from these efforts and to offer insight for future pandemics. This review focuses on nanomaterial-based optical biosensors, which are central to multiple emerging diagnostic tools. It covers techniques such as lateral flow immunoassays (LFIA), plasmonic biosensors based on surface plasmon resonance (SPR) and localized SPR (LSPR), surface-enhanced Raman spectroscopy (SERS), and surface-enhanced fluorescence (SEF). LFIAs played an important role in the COVID-19 pandemic and will continue to shape biosensing in future pandemics, while other techniques are yet to reach commercialization despite recent strides.