RESPONSE OF CHEMICALLY-MODIFIED PRPC(2), PRPC(2)(T) AND GDPC(2)(T) LANGMUIR-BLODGETT-FILMS TO TOBACCO-SMOKE

A modification of previously reported tobacco-smoke sensors based on L angmuir-Blodgett (LB) films of praseodymium bisphthalocyanine (PrPc(2) ), octa-tert-butyl praseodymium bisphthalocyanine (PrPc(2)(t)) and oct a-tert-butyl gadolinium bisphthalocyanine (GdPc(2)(t)) is presented. P rior to the exposure to tobacco smoke, chemical or electrochemical oxi dation of the LB assemblies is proposed in order to improve the detect ion of the colour change in the optical region. Differences in the int eraction of main stream (MS) and secondary stream (SS) smoke of two to bacco brands have been detected. Increasing amounts of smoke give rise to progressive responses of the modified LB films. The effect of temp erature on the adsorption of smoke has also been studied. The applicat ion of these modified sensors in the evaluation of environmental tobac co smoke (ETS) is analysed.