Biochemical sensors are used for discrimination of biochemical species, concentration measurement, and so on. Because metamaterial responds to slight changes in the ambient refractive index, it is possible to realize ultrasensitive biochemical sensors. We designed and fabricated refractive index sensors using polarization independent metamaterial and examined their application as biochemical sensors. Refractive index sensitivity, concentration measurement, and DNA detection were carried out. K E Y W O R D S biosensors, chemical sensors, metamaterial, optical sensors, plasmon 34 wileyonlinelibrary.com/journal/ecj Electron Comm Jpn. 2019;102:34-40.