Odorant-sensing cell micropatterns for odor discrimination

A technology that can effectively distinguish between various odorants with high sensitivity and selectivity has numerous applications ranging from water quality testing to disease diagnosis. Here, we report a cell-based odorant-sensing display that utilizes Sf21 cells expressing odorant receptors, co-receptors, and a calcium-sensitive fluorescent protein as the sensing elements for detecting multiple odorants. Integrated micropatterns of the sensor cells in a few hundred micrometer-size patterns were fabricated on photoactivatable cell-anchoring surfaces consisting of photo-responsive polymeric materials. In the microfluidic system equipped with the sensing display, the injection of two model odorants, such as Bombykal and 1-octen-3-ol, at micro-molar concentrations resulted in selective and rapid fluorescence emission from the corresponding sensor cell patterns. Furthermore, when both odorants were injected together, the fluorescence from each corresponding sensor cell could be observed simultaneously. This study provides the proof of principle that the current cell patterning system enables the discrimination of odors, including multiple odorants, through a finely patterned sensing display on the device.