We study biosensors that detect biomolecules electrochemically. Electrochemical sensors have attracted attention due to its non-destructive and rapid target detection. These sensors performance varies greatly depending on the immobilization of biomolecules on the electrodes and transforming the information obtained through the biomaterials function into electrical signals. In short, our theme of research is how to combine biomaterials and organic/inorganic materials and make them function as sensors. We are also working on developing simple and rapid method for measuring the biological function and the concentration of target molecules in biological environments.