Surface acoustic wave biosensor based on odorant binding proteins deposited by laser induced forward transfer

In this paper, a biosensor for vapor phase detection of odorant molecules based on Surface Acoustic Wave (SAW) resonators is presented. The SAW resonators were coated with a wild-type odorant-binding protein from pig (wtpOBP) deposited by laser-induced forward transfer (LIFT). Two protein solutions, i.e. with 20% and 50% (v/v) glycerol, were deposited by LIFT changing the laser fluence and the printing morphology of droplets. The SAW biosensor was tested in nitrogen upon exposure to R-(-)-1-octen-3-ol (octenol) and R-(-)-carvone (carvone) vapors in the range of concentrations between 9 and 60 ppm. An uncoated device was used to compensate the responses due to variations in environmental parameters. The differential response curves showed a linear behavior in the tested range of concentrations and the obtained sensitivities were of 20.7 Hz/ppm and of 13.8 Hz/ppm, respectively, for octenol and carvone.