4.2.4 Piezoelectric Olfactory Receptor Biosensor with Aptamer assisted Immobilization Technique

Abstract

This paper presents an olfactory receptor-based piezoelectric biosensor for sensitive odor detection, in which aptamer-assisted olfactory receptor immobilization method is employed for the purpose of performance enhancement. Olfactory receptors (ORs) with a his-tag were employed as the sensitive elements. Anti-his aptamers were immobilized covalently onto the gold surface of piezoelectric quartz crystal microbalance (QCM) electrode to capture his-tagged ORs specifically. By this method, the covalent immobilization as well as the purification of ORs was obtained simultaneously. The results demonstrated that aptamer-assisted OR immobilization technique can improve the performances of the biosensor greatly. Specifically, the detection limit of this OR-based biosensor is as low as 2-3 ppm.