Technologies for detecting pesticide residues to ensure the security and safety of foods have also been developed by applying the taste sensor. Pesticides are composed of 1) active ingredients (AIs), 2) inert ingredients added to support the AIs and facilitate the formulation, and 3) surfactants; the latter two are called pesticide adjuvants. The taste sensor detects the changes in the electrical potential of lipid/polymer membranes caused by the physicochemical interaction between the membranes and chemical substances. By applying this principle, we develop a technology that can detect pesticide residues that exceed the acceptable level and aim to realize portable pesticide sensors.