This study describes a gas-flow device that enhances the solubility of gas-phase odorants into aqueous solution for cell-based sensors. Cell-based sensors using olfactory receptors have attracted attention because of their high sensitivity and selectivity. However, most of previous studies used liquid-phase odorants as a target sample due to their low solubility of gas-phase odorants even though the applications expect the gas-phase sensing. Therefore, we focus on gas-phase odorant detection using the gas-flow device. Here, we clarify the impact of the velocity of convection inside the solution to enhancement of the solubility, based on computational simulation. Moreover, we experimentally verify efficiency of odorant dissolution in two types of devices, compared with the negative control using a sample odorant.