Biosensors based on odorant binding proteins

Abstract

Both the sensillary lymph of insects and the nasal mucus of vertebrates contain large amounts of small soluble proteins, odorant-binding proteins that specifically and reversibly bind odors and pheromones. Proteins from different sources have affinities toward a wide range of compounds with different sizes and shapes. They can be easily expressed in heterologous systems, they show high thermal stability and it is possible to modify their binding sites by site-directed mutagenesis. We describe the development of an odor sensing biosensor array based on immobilization of odorant binding proteins on to suitable transducers. Using a quartz crystal microbalance platform as a transduction element, it is possible to detect and measure quantitatively concentrations of volatile analytes at parts per million concentrations in air.