PROBLEM TO BE SOLVED: To solve a problem wherein a conventional surface plasmon resonance (SPR) sensor using linearly polarized light cannot sensitively detect circular dichroism, though the SPR sensor can measure refractive index (or dielectric constant) and its variation on a metal surface or near the interface, and easily measure the interaction between various chemical substances and hence can be used as "chemical sensor" capable of sensitively measuring it in real time by biotechnology related researchers. SOLUTION: In the SPR sensor, by forming a shape structure having single or a plurality of periodicities on its metal surface and applying an external magnetic field to the metal part, circularly polarized wave of plasmon is induced around the periodic shape structure, and the circular dichroism is detected by the interaction between evanescent wave from it and an optically active substance. Thus, the circular dichroism of a medium having optical activity can be measured, and L bodies and D bodies as optical isomers of organic substances such as sugar, protein, and amino acid can be distinguished. COPYRIGHT: (C)2009,JPO&INPIT
