This paper reports an attempt to improve the response of a metalloporphyrin
Langmuir-Blodgett films, n-tetraphenyl porphine ruthenium (II) carbonyl,
towards several vapor samples by means of surface microstructure
modification. Four different surface microstructures were prepared by
annealing the thin films samples in air at three different temperatures; 50,
100 and 150 $^{\circ}$
C, for one hour. Three types of vapor samples with different
physico-chemical properties, namely saturated vapor of methanol, ethanol and
2-propanol in 15 l/min of air flow, were used. The sensing sensitivity was
based on the change in the optical absorption of the film upon exposure
towards the gas samples that was measured at a particular wavelength, i.e.,
514 nm, of the light source. It was observed that the response of the thin
films was influenced by its surface microstructure, which the smoother the
surface the higher the response is. The correlation between the
microstructure of the films surface and its gas sensing property will be
discussed.