Olfactory receptor based piezoelectric biosensors for detection of alcohols related to food safety applications

Our major goal in developing intelligent quality sensors is to detect bacterial pathogens such as Salmonella in the packaged beef. Olfactory sensing of specific volatile organic compounds released by the bacterial pathogens is one of the unique ways for determining contamination in food products. This work aims at developing a biomimetic piezoelectric olfactory sensor for detecting specific gases (alcohols) at low concentrations.The computational simulation was used to determine the biomimetic peptide-based sensing material to be deposited on the quartz crystal microbalance (QCM) sensor. Tripos/Sybyl^®8.0 was used to predict the binding site of an olfactory receptor and determine the binding affinity as well as orientation of the selected ligands (specific molecules) to the olfactory receptor. The designed polypeptide sequence based on the simulation program was synthesized and used as a sensing layer in the QCM crystal. The developed QCM sensors were sensitive to 1-hexanol as well as 1-pentanol as predicted by the simulation algorithm. The estimated lower detection limits of the QCM sensors for detecting 1-hexanol and 1-pentanol were 2-3 ppm and 3-5 ppm, respectively. This study demonstrates the applicability of simulation-based peptide sequence that mimics the olfactory receptor for sensing specific gases.