Nanoscale optical biosensors based on localized surface plasmon resonance spectroscopy

The Ag nanoparticle based localized surface plasmon resonance (LSPR) nanosensor yields ultrasensitive biodetection with extremely simple, small, light, robust, and low-cost instrumentation. Using LSPR spectroscopy, the model system, biotinylated surface-confined Ag nanotriangles, was used to detect less than one picomolar up to micromolar concentrations of streptavidin. Additionally, the monitoring of anti-biotin binding to biotinylated Ag nanotriangles exhibited that the system could be used as a solution immunoassay. The system was rigorously tested for nonspecific binding interactions and was found to display virtually no adverse results. These results represent important new steps in the development of the LSPR nanobiosensor for applications in medical diagnostics, biomedical research, and environmental science.