Array of sensors based on lanthanide bisphtahlocyanine Langmuir-Blodgett films for the detection of olive oil aroma

In this paper a sensor array based on Langmuir-Blodgett (LB) films of lanth anide bisphthalocyanines (LnPc(2)) aiming to discriminate among diverse vir gin olive oils has been designed. For this purpose, sensors based on bispht halocyanines including unsubstituted bisphthalocyanines with different cent ral metal atom (PrPc2 and LuPc2) and a octatertbutyl substituted bisphthalo cyanine (PrPc2') have been prepared. The interaction of the sensors with th e headspace of olive oil samples has been studied by registering the change s in the conductivity produced in the LB films, The influence in the respon se of parameters such as the number of monolayers or the proportion of arac hidic acid used in the preparation of the LB films has been analysed. Studi es on the stability and reproducibility of the LB film-based sensors have b een carried out. Using the previous results, the sensors with the best performance character istics have been selected, and an array of five sensors has been constructe d. The array has been exposed to four types of Spanish olive oils with diff erent organoleptic properties and qualities. The principal component analys is of the obtained signals has allowed the discrimination of the different types of olive oils. (C) 2001 Elsevier Science B.V. All rights reserved.