A Light-Addressable Potentiometric Sensor for Odorant Detection Using Single Bioengineered Olfactory Sensory Neurons as Sensing Element.

A light-addressable potentiometric sensor (LAPS), a silicon-based surface potential detector, is combined with bioengineered olfactory sensory neurons (OSN) for odorant detection. A LAPS chip is used as a transducer to monitor cell membrane potential changes. In addition, a focused movable laser with a diameter comparable to cell sizes is employed to select the desirable single cell for measurement under a microscope. Bioengineered OSNs are coupled to the LAPS surface and employed as sensing elements, which are prepared by the expression of an olfactory receptor of C. elegans, ODR-10, on the plasma membrane of rat primary OSNs via transient transfection. The responses of bioengineered OSNs to diacetyl, isoamyl acetate, and acetic acid are monitored by extracellular recording using the LAPS chip. Features of the recorded extracellular potential firings are analyzed in frequency and time domains. We have shown that bioengineered OSNs can generate specific response signals upon the stimulation of diacetyl, which is the natural ligand of ODR-10. Moreover, different concentrations of diacetyl can elicit different temporal firing patterns in bioengineered OSNs, which permits the concentration detection of specific odorant molecules in solution.