SERS (surface-enhanced Raman scattering)-based lateral flow assays

Lateral flow immunoassays (LFIA) have revolutionized the field of point-of-care diagnostics by offering rapid and user-friendly detection of various analytes, from infectious agents to biomarkers and environmental pollutants. However, the quest for enhanced sensitivity and quantitative capabilities has driven the integration of novel techniques into LFIA platforms. Surface-enhanced Raman scattering (SERS), a powerful spectroscopic technique, has emerged as a promising candidate to overcome the limitations of conventional LFIA. This chapter provides an overview of the recent advances in lateral flow immunoassay surface-enhanced Raman scattering (LFIA-SERS), highlighting the synergistic potential of this integration. It delves into the fundamental principles of LFIA and SERS, illustrating how the combination of these techniques can transform traditional lateral flow tests into highly sensitive and specific diagnostic tools. The first part of the chapter discusses the fabrication and optimization of SERS-active substrates for LFIA-SERS. Various nanomaterials, such as inorganic nanoparticles and nanostructured surfaces, are explored, emphasizing their role in enhancing Raman signals and providing a solid foundation for the development of ultrasensitive LFIA-SERS platforms. Next, the chapter showcases the application of LFIA-SERS in diverse diagnostic fields. Case studies are presented, demonstrating the detection of clinically relevant biomarkers and pathogens with significantly improved sensitivity and specificity compared to conventional LFIA. The ability to multiplex and quantitate analytes using LFIA-SERS is also addressed, showcasing its potential for comprehensive diagnostic profiling. The chapter concludes with an outlook on the future directions of LFIA-SERS. It highlights the challenges that must be addressed, such as standardization, cost-effectiveness, and commercialization. Additionally, the potential for LFIA-SERS to pave the way for novel applications, such as on-site monitoring of environmental contaminants and personalized medicine, is explored.