To analyze the physio-chemical measures of the cellular environment and display them in digital units, transducing methods are applied in biosensors. The labelfree biosensors employ biophysical characteristics such as spectroscopic methods, crystallization, and Surface plasmonic resonance (SPR) to determine the availability or concentration of substances. SPR is a method to elucidate interaction among biomolecules exhibiting affinity binding, structural changes, or alteration in pathological conditions. SPR methods are now employed in conjunction with a variety of transducer topologies, including optical fibers, nanoparticle-based SPR, immobilized or localized SPR (LSPR), long-range SPR, image SPR, immune-assay-based SPR, and phase sensing SPR biosensors' versatile configuration allows for the early detection of several illnesses, such as COVID-19, dengue, non-invasive cancer, biomarker-based fetuses identification, therapeutic antibody characterization, drug monitoring, etc. SPR system is leading in diagnostics and therapeutics with various advantages, such as their portable size, cost-effectiveness, quick result, and easy-to-handle method, but at extension, this technique needs development to ensure high sensitivity, averting background effect and evolution of label-free direct detector to quantify real sample. This chapter reviews the model’s instrumentation and bioassay of clinical samples from SPR and its associated biosensor.
Keywords: Biosensor, Diagnostics, Surface plasmonic resonance (SPR).
