GAS-DETECTION BY A MULTI-HYBRID SENSOR WITH DYE LANGMUIR-BLODGETT-FILMS DEPOSITED ON A QUARTZ OSCILLATOR

A hybrid gas sensor combined an optical detector with a weighing syste m for adsorbed gas is realized by dye LB-films deposited on a quartz o scillator. With this sensor, the change of fluorescence intensity from dye LB-film is simultaneously measured with the change of oscillation frequency of the quartz oscillator which depends on the amount of ads orbed gas in the LB-film. Squarylium dye LB-film and perylene dye LB-f ilm were applied for this hybrid gas sensor. The quartz oscillators wi th LB-film commonly showed decrement of their oscillation frequency co rresponding to the adsorption of gases. On the other hands, changes of fluorescence intensity depend on the type of gases, the dye molecules and its aggregation forms. These results suggest advantage of a multi -hybrid gas sensor using multiple quartz oscillators with different dy e molecules. In this report, we discuss the responses of hybrid gas se nsor in connection with the semiconductivity of the dye and its aggreg ate in LB-films.