Development of sensor surface with recognition of molecular substructure

A biological olfaction system is one of the highest performance chemical sensing systems for low-molecular-weight compounds. An ability of recognizing a various molecular properties based on their structures is essential for a biological odor recognition process. For the development of a sensor mimicking the olfactory system, we have formed benzene-patterned self-assembled monolayer (SAM) on the sensor surface using SAMs with nanostructure that serves as adsorption sites for benzene ring, which is representative substructure of aromatics. The structure of the benzene-patterned SAM surface was analyzed by contact-angle measurement, ellipsometry, cyclic voltammetry (CV) and atomic force microscopy (AFM). Moreover, the electrodes evaluated as sensor surfaces with cyclic surface-polarization impedance (cSPI) sensor that measures changes in impedance of the electrode surface by adsorption of substances. The results of cSPI indicated the benzene-patterned SAM surface could distinguish benzene by recognizing of the hydrophobicity and the molecular size.