Recent Trends and Impact of Localized Surface Plasmon Resonance (LSPR) and Surface-Enhanced Raman Spectroscopy (SERS) in Modern Analysis

An optical biosensor is a specialized analytical device that utilizes the principles of optics and light bimolecular processes. Localized surface plasmon resonance (LSPR) is a phenomenon in the realm of nanophotonics that arises when metallic nanoparticles (NPs) or nanostructures interact with incident light. On the other hand, surface-enhanced Raman spectroscopy (SERS) is an influential analytical technique rooted in Raman scattering, wherein it amplifies the Raman signals of molecules when they are situated near specific and specially designed nanostructures. A detailed exploration of the recent ground-breaking developments in optical biosensors employing LSPR and SERS technologies has been exhaustively discussed along with their underlying principle and the working mechanism. A biosensor chip has been created, featuring a high-density deposition of gold nanoparticles under varying ligand concentration and reaction duration on the substrate. An ordinary description, along with a visual illustration, has been thoroughly provided for concepts such as a sensogram, refractive index shift, surface plasmon resonance (SPR), and the evanescent field, Rayleigh scattering, Raman scattering as well as the electromagnetic enhancement & chemical enhancement. LSPR and SERS both have their advantages and disadvantages but widely used SERS has some advantages over LSPR like chemical specificity, high sensitivity, multiplexing, and versatility in different fields. This review confirms and elucidates the significance of different disease biomarker identification. LSPR, and SERS both play a vital role in the detection of various types of cancer like cervical cancer, ovarian cancer, endometrial cancer, prostate cancer, colorectal cancer, and brain tumors. This proposed optical biosensor provides potential application for early diagnosis and monitoring of viral disease, bacterial infectious diseases, fungal diseases, diabetes, and cardiac disease biosensing. LSPR and SERS provide a new direction for environmental monitoring, food safety, refining of impurities from water samples, and detection of lead. The understanding of these biosensors is still limited and challenging.