Taste sensing with HDTC modified polyvinyl alcohol-polyacrylic acid membrane

There are reports of taste sensor fabrication by incorporating lipids in PVC matrix. We have taken an attempt to prepare taste sensor material by using functionalized polymer. Polyvinyl alcohol (PVA) and polyacrylic acid (PAA) have been modified to fabricate the sensor material. The research work covers polymer membrane preparation, morphology study, and structural characterization of membrane and study of the taste sensing characteristics. The membrane was prepared by cross-linking polyvinyl alcohol and polyacrylic acid in aqueous-organic medium by using hexadecyltrimethylammonium chloride (HDTC) with proper heat treatment. The cross-linked PVA-PAA was phosphorylated with POCl₃. PVA-PAA membranes of suitable thickness were thus prepared with good threshold sensing value and less swelling in water. FTIR spectroscopic analysis, XRD analysis and optical microscopy were done to get an idea about the structure and morphology of the polymer membrane. Sensor device prepared with this membrane has shown distinct response patterns for different taste substances in terms of membrane potential. The sensor characteristics like temporal stability, response stability, response to different taste substances, and reproducibility of sensing performance were studied. Membranes also showed characteristic response patterns for organic acids like acetic acid, citric acid, formic acid, etc., mineral acids like HCl, H₂SO₄ and HNO₃, etc., salt, bitter substance, sweet substance, umami substance and different grades of tea. Sensor device prepared with this membrane has excellent shelf life.