Gravimetric organic gas-sensing devices capable of detection at sub-ppm levels can be produced by radio-frequency sputtering of α-amino acids onto quartz crystal plates. By controlling the substituents of the α-amino acids, the molecular structure and sorption characteristics of the amino acid films can be tailored. Phenylalanine and tyrosine films maintain their original structures, and their sorption properties are mainly governed by the degree of hydrogen bonding. Non-benzenoid amino acid films become polarizable due to their deficiency in oxygen caused by plasma processing. Multiple linear regression analysis, based on linear solvation energy relationships, can predict the sorption capacities quantitatively.