Surface plasmon resonance

Abstract Surface plasmon resonance (SPR) biosensors enable real-time, highly sensitive measurements of biomolecular interactions across a broad range of molecule sizes, without labeling and with no destruction of original form and its function of materials. SPR biosensors detect the specificity, affinity, and kinetic parameters of many bond types, including protein–protein, protein–DNA, enzyme–substrate or inhibitor, receptor–drug, lipid membrane–protein, protein–polysaccharide, and cell– or virus–protein interactions. Functionally, SPR is the resonant oscillation of free electrons that occurs at the interface between negative and positive permittivity materials when stimulated by light. When a sample of analytes flows over immobilized ligands on a prepared surface illuminated by specific light wavelengths, analyte–ligand binding causes shifts in the SPR angle. These shifts are used to detect binding events. Significant technologic advances in laser technology, optical systems, and miniaturized digital information modalities have been integrated in SPR biosensors that are easy-to-use, sensitive, and cost-effective. SPR biosensors are being developed for clinical point-of-care applications, such as detecting biomarkers in blood or cerebrospinal fluid for many conditions, including traumatic brain injury.