Chemical Oscillation Device of Lipid Across a Micropore and its Chemical Sensing Functions

Abstract

Oil/Water interface was formed across a micropore constructed by semiconductor technology. Nitrobenzen was used as oil phase, and 5mM CTAB was used as water phase. By using the pore, remarkably stable potential oscillations of a lipid membrane were obtained. Resting potential, amplitude and period of oscillation were observed to be stable for more than 120hours. In this paper, we applied this self-excited potential oscillation device as chemical sensor, and report the effect of chemical substance added into the water phase. The effect of taste stimulants added to the water phase with CTAB was investigated as a model for the biological chemoreceptive membranes. Magunesium sulfate, saccharose, citric acid, potassium chloride glutamic acid monosodium salt were chosen as bitter, sweet, sour, salty and umami substances, respectively. Frequency characteristics were examined by FFT to determine fundermental frequency accurately. The experimental results with microscopic observation show that the sensing system using the micropore can distinguish different chemical substances as well as their concentrations, suggesting its application to a chemical sensor. It was found that waveshapes response of chemical substance added to the water phase was correspondent to the condition of aggregated lipid around a micropore.