Plasmonic Metal Nanoparticles in Spectroscopic Biosensing: innovation in Label Free Detection

Plasmonic Metal Nanoparticle (PMNPs) have emerged as transformative agent in the realm of spectroscopic biosensing, offering unparalleled sensitivity, tunable optical properties and surface enhanced signal amplification. This review explores recent innovations in label free detection strategies that harness the Localized Surface Plasmon Resonance (LSPR) and Surface-Enhanced Raman Scattering (SERS) phenomena intrinsic to (PNPs). Emphasis is placed on the design, functionalization and integration of gold, silver and hybrid nanostructures within spectroscopic platform for real-time, noninvasive biomolecular recognition. Advances in fabrication techniques, bio interface engineering and multiplexed detection are critically examined, alongside emerging applications in clinical diagnostic, environmental monitoring, and point of care technologies. The review also highlights challenges related to reproducibility, biocompatibility, and regulatory translation, offering insights into future detection for scalable, robust and miniaturized biosensor development. By bridging nanophotonics with analytical biochemistry, (PMNP-based spectroscopic biosensing is poised to redefine the landscape of rapid, label free diagnostics.