DOPED (CONDUCTING) AND UNDOPED (SEMIINSULATING) LB FILMS - APPLICATION TO GAS-SENSING

The present paper deals with the use of semi-insulating and conducting LB films as conductimetric sensors. The response of such sensors consists in conductivity changes induced by gas exposure. Examples collected in the literature are presented and show that the LB technique is very convenient for making continuous ultrathin organic materials exhibiting detection properties towards toxic gases (NO2, PH3,...). Very interesting results have been obtained using mixed LB films even if the conducting properties of the resulting material and the detection mechanism are not well understood. Some multifunctional materials are required exhibiting conduction properties for transduction and 'recognition properties' for selective detection. With that goal, the LB technique associated with organic chemistry provides undeniable advantages.