Relationship Between Sensor Sensitivity and Chemical Structure of Benzene-Carboxylic Modifiers for Umami Substance Detection

A 2,6-dihydroxyterephthalic acid (2,6-DHTA)-treated taste sensor exhibited sensitivity and selectivity for umami substances, as previously reported. This study aims to investigate the relationship between the sensor’s sensitivity to umami substance and the chemical structure of modifiers—specifically ortho, meta, and para substituents. The investigations focused on using structurally different modifiers to measure monosodium L-glutamate (MSG) at various concentrations. Additionally, based on the investigation of lipid and modifier conditions, a 1 mM lipid concentration was chosen for fabricating the lipid/polymer membranes used in MSG measurements, and each membrane was treated with a 0.03 wt% modifier solution. The results revealed that the sensor’s sensitivity varied depending on the modifier structures as well as the presence of an intramolecular H-bond within these modifiers, indicating the critical role of modifier structures in effectively detecting umami substance with the taste sensor.