Biosensors Based on Noble Metal Nanoparticles

摘要

Noble metal nanoparticles exhibit a characteristic absorption band in the absorption spectrum, known as "localized surface plasmon resonance (LSPR)". The absorbance and peak wavelength of the LSPR band are linearly dependent on the refractive index of the surrounding medium. The sensing sensitivity can be increased by using nanoparticles of different shapes and by using waveguides to increase the optical path. The nanoparticles can also be functionalized to allow the selectivity of the sensor. Since the detection process is based on the change of refractive index of the surrounding medium when the analyte interacts with the molecular recognition group on the nanoparticle surface, the analyte does not require to have a spectroscopic signature (e.g. fluorophore, chromophore, etc.). Thus, noble metal nanoparticles can be used to construct label-free sensors.