Patent ID: 7508043

Claim:
A sensor for detecting a localized plasmon resonance state of a metal particle surface by light and analyzing properties of a sample present near metal particles employing a sensor chip, comprising: means for irradiating measuring light having a predetermined wavelength band to the rods of metal particles of said sensor chip; sensor-chip hold means for holding said sensor chip so that the longitudinal axes of said metal particle rods are inclined with respect to an electric field direction of said measuring light, and so that the angle of inclination can be freely changed; drive means for driving said sensor-chip hold means so that said angle of inclination is changed; light detection means for spectrally detecting an intensity of said measuring light transmitted through said metal particle rods or reflected at said metal particle rods; and control means for setting a direction of said sensor-chip hold means so that said angle of inclination is fixed, by controlling operation of said drive means based on said intensity detected by said light detection means; wherein the sensor chip comprises: a support with a plurality of pits individually and independently formed in one surface thereof so that they extend toward an interior thereof; and a plurality of rods of metal particles, whose aspect ratio is not 1, respectively held in said plurality of pits so that an end surface of each rod is exposed at said one surface of said support and a longitudinal side surface of each rod is covered with said support.