The Potential of Optical Technologies in Early Virus Detection; Prospects in Addressing Future Viral Outbreaks.

The urgent need for sensitive, rapid, and reliable diagnostic methodologies to control and prevent life-threatening pandemic infectious disease, such as COVID-19, remains a critical priority. Timely and on-site detection of viral pathogens is essential for effective disease management and mitigation of societal disruptions. Recent advancements in optical diagnostic methods have positioned them at the forefront of healthcare diagnostics, offering high sensitivity and specificity as viable alternatives to conventional techniques such as the Polymerase Chain Reaction (PCR), which often suffer from time delays and limited accessibility in resource-constrained environments. This review elucidates the potential of various optical diagnostic techniques, highlighting their advantages over traditional methods. It encompasses a range of optical modalities, including fluorescence-based approaches, Raman spectroscopy (RS), Plasmonic techniques (e.g., surface plasmon resonance (SPR), localized SPR, (LSPR), surface-enhanced Raman spectroscopy (SERS), and surface-enhanced fluorescence (SEF)), super resolution microscopies (SRMs), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and integrated platforms such as waveguides and molecularly imprinted polymer (MIP)-based biosensors. Additionally, the evolution of novel biosensors, particularly 5th and 6th generation biosensors, in healthcare and the challenges related to these technologies were discussed. This studies reviewed aims to advance the development of portable, sensitive, specific, and cost-effective point-of-care (POC) diagnostic devices for the rapid detection of viral pathogens.