Cells smell on a CMOS: A portable odorant detection system using cell-laden collagen pillars

We developed a portable odorant detection system composed of collagen micro-pillars with cells expressing olfactory receptors and a CMOS imaging sensor; the CMOS imaging sensor caught fluorescence signals of Ca
²⁺
increased by odorant molecules. While low sensitiveness of the CMOS imaging sensor was insufficient to detect the fluorescent signal from a single cell, the odorant detection system achieved supply of sufficient odorant-induced fluorescence intensity to the CMOS imaging sensor by vertical accumulation of the fluorescence from each cells in the pillars. We believe that our portable odorant detection system will be a useful platform for quantitative and selective portable odorant sensor.