Bridging pandemic and oncology challenges: Surface-enhanced Raman spectroscopy in the fight against COVID-19 and cancer.

While Raman spectroscopy itself stands on the principle of inelastic scattering of light, surface-enhanced Raman spectroscopy (SERS) amplifies those normally rather weak Raman signals by way of interactions between molecules and nanostructured metal surfaces. The technique has rapidly evolved into a very powerful analytical tool with enormous potential in combating cancer and COVID-19. SERS is a useful tool for diagnostics and treatment monitoring because of its remarkable sensitivity and ability to detect low-abundance molecules; nevertheless, standardizing techniques, guaranteeing reproducibility across several platforms, and overcoming problems related to signal enhancement and sensitivity under different experimental conditions remain challenges. SERS is also being explored about the COVID-19 pandemic, where its high sensitivity and specificity hold a promise in diagnostics, treatment monitoring, and even environmental tracing of the virus. When it comes to treatment, SERS-based theragnostic applications offer a two-pronged approach by combining therapeutic interventions with diagnostic capabilities that would make different therapies more accurate and effective. Approaches to SERS-guided drug delivery systems are discussed that would allow the drug to reach exactly where the antiviral agent is wanted, hence reducing side effects and enhancing treatment outcomes. Other approaches examined, including nanoparticle-based SERS for targeted therapy and the design of SERS tags, allow therapy and develop new ways of treatment against this virus. Finally, potential future developments of SERS technology and its wider applications in cancer and virology are discussed, with a specific view on the impact SERS might have on how infectious diseases are treated. In addition to discussing its present and potential uses, this narrative review emphasizes the critical role that SERS plays in developing and tracking cancer and COVID-19 treatments.