Spun films of novel calix[4]resorcinarene derivatives for benzene vapour sensing

Surface plasmon resonance (SPR) experiments have been performed on spin-coated thin films of novel calix[4]resorcinarene derivatives having four azo-dye substituting groups for the detection of benzene vapour at low concentrations. The films are produced by spinning a carefully prepared solution of calix[4]resorcinarene in chloroform at 2000 rpm and found to be 12 nm thick. Exposure to benzene vapour has resulted in a fast and reversible adsorption, with a typical response time of a few seconds. The mechanism of vapour adsorption onto the spun films is considered to be due to a host–guest interaction between the organic vapour molecules and the azo-calixresorcinarene molecular cavity. The response is found to be linearly dependent on benzene vapour concentration up to 400 ppm.