Three kinds of novel amino acid-bearing macrocyclic 1,3 bridged calix[4]arenes are employed as piezoelectric quartz crystal sensor (PQC) coatings for detection of organic amines and alcohols in gas. The results of frequency changes corresponding to the mass of sorbed gas are compared. The frequency shift increases as the molecular weight of the organic vapor increases. The three coatings studied show preferential affinity for the amines and alcohols with normal structure. This is because that the linear alkyl chains have less steric hindrance and can be incorporated probably in the cavity of calix[4]arenes to form endo calix complexes, or directly interact with the amino acid bearing derivative cycle by hydrogen bonding. The more branched the structure of the alkyl groups is, the lower the responses are. The results show that the selective absorptions between the coatings and guest molecules are based on steric effect of the analytes, hydrogen bonding and hydrophobic force. The frequency responses of all the analytes on cystine bearing calix[4]arenes are much greater than on the other two coatings, indicating that conformation of 1,3 bridged calix[4]arenes and the size and the property of the derivative cycles also have influence on the responses when the coatings adsorb isomers. The measuring concentration and temperature are optimized and 2 56×10^-5 mol/L, 25℃ are selected respectively.

Key words: amino acid-bearing 1, 3-bridged calix[4]arene, piezoelectric quartz crystal sensor, selective recognition