Responses of Monolayer Membrances of Thiol-Containing Lipids to Odor Substances

It is known that thiol-containing compounds form monolayer membranes on a gold surface via chemisorption from organic solvents in terms of a strong connection ability between thiol and the metal. Here we prepared different kinds of thiol-containing lipids and fabricated monolayer membranes on the gold disk electrode whose surface structures were similar to biological membranes. Responses of this lipid-coated electrode to odor substances were examined by an electrochemical method of a cyclic voltammetry. Blocking ability for the redox reaction of Fe(CN)₆ ³⁻ was found to change upon adsorption of odor substances into monolayer membranes. The order of threshold values to detect the odorants was β-iononeβ-citralβchloroform≦n-amyl acetate; this order was the same as that in the human olfactory sense. The present study indicates that the monolayer membrane of thiol-containing lipids can be useful as a transducer of an odor sensor.