Odor sensors based on molecular wire and nanofibers

Chemical sensors that can be applied for an odor sensing must detect a very small portion of the bulk adsorbent. In order to realize this point it is necessary to observe an interaction between analytes and sensor surfaces sensitively. A candidate to achieve such chemical sensing is a switching behavior of a functional molecular that occurs on conductive molecules by adsorbing chemicals. If the electronic properties of the molecule are affected by such switching behavior, conductance will be easily changed. A charge transfer (CT) interaction between chemicals is a general concept for the conductance change, in which doping effect that causes donor or acceptor, Coulomb repulsion by electron correlation, or acid base reaction affects electrical conductance of materials. In the most typical case appeared in low dimensional conduct, CT interaction causes insulator-conductor transition, e.g., Mott transition, of materials, i.e., molecular switching phenomena. On the other hand, a nanostructured sensor surface is necessary to detect molecular conductance change caused by tiny analytes adsorption. In this study, we suggest sensor investigation for various volatile compounds by a transition of molecular wire conductance induced by electron-correlation interaction formation.