Two phthalocyanines and a porphyrin with different central metal atoms (Cu, Ni and Co, resp.) were deposited by the Langmuir-Blodgett technique directly onto the quartz crystals of a piezoelec. app. and used as the active layer for the detection of phenols in liq. phase.� For the studied active layers, the subsequent statistical anal. revealed that in the sensing performances the responses of the two different phthalocyanines were redundant
