Sensor for detecting a target substance in a fluid

A device for detecting a target substance in a fluid, comprising

• a flow path for passing a fluid containing the target substance,
• a periodic structure placed at least a portion of the flow path and having a vacant portion for passing the fluid containing the target substance and a solid portion capable of transmitting an electromagnetic wave arranged regularly to form a periodic distribution of a refractive index for the electromagnetic wave,
• an electromagnetic wave-projecting means for projecting the electromagnetic wave to the periodic structure, and
• a detecting means for measuring the magnetic wave emitted from the periodic structure to detect a change in the periodic distribution of a refractive index.

A device for detecting plural target substances in a fluid, comprising

• a flow path for passing a fluid containing the target substances;
• plural periodic structures each of which is placed at least a portion of the flow path and has a vacant portion for passing the fluid containing the target substances and a solid portion capable of transmitting an electromagnetic wave arranged regularly to form a periodic distribution of a refractive index for the electromagnetic wave,
• an electromagnetic wave-projecting means for projecting the electromagnetic wave to the periodic structures, and
• a detecting means for measuring the magnetic wave emitted from the periodic structures to detect a change in the periodic distribution of the refractive index.