Spheroids on a CMOS chip for a portable odorant sensor

We propose a fluorescence detection system for a portable odorant biosensor composed of cell spheroids with expressed olfactory receptors and a CMOS chip. As fluorescence intensity of spheroids is higher than that of single cells, we achieved detection of fluorescence signals caused by intracellular chemical reaction on the CMOS chip. As a demonstration of odorant detection, we prepared spheroids of cells expressing olfactory receptors to certain odorant molecules. The CMOS chip could detect the increment of the fluorescence intensity around the spheroids when odorant molecules were applied. We believe that the system will contribute to establish portable odorant biosensors.