Gas sensitivity measurements on NO2 sensors based on copper(II) tetrakis(n-butylaminocarbonyl)phthalocyanine LB films

The NO2 gas-sensing characteristics of chemiresistors in the form of multil ayered Langmuir-Blodgett films of a symmetrically substituted phthalocyanin e, containing on the periphery four amidic groups -CONH-, have been studied . Floating layers were spread onto the water surface from a chloroform solu tion and were transferred onto both hydrophilic and hydrophobic quartz subs trates using the vertical lifting method. Response and recovery times have been measured for different working temperatures at a fixed NO2 concentrati on. Dynamic response characteristics of the electrical conductance of the L B films to different NO2 concentrations, carried out in dry air, have shown a high sensitivity to concentrations of nitrogen dioxide smaller than 20 p pm at room temperature. All measurements have been carried out using coplan ar configurations of the devices.