Layer-By-Layer Films of Silsesquioxane and Nickel(II) Tetrasulphophthalocyanine as Glucose Oxidase Platform Immobilization: Amperometric Determination of Glucose in Kombucha Beverages

This paper describes the development of a novel glucose biosensor through layer-by-layer technique (LbL). The self-assembled architectures were composed positive-charged silsesquioxane polyelectrolyte, 3-n-propylpyridinium chloride (SiPy+Cl−), nickel (II) tetrassulphophthalocyanine (NiTsPc), and conductive surface FTO (fluor tin oxide). construction was influenced by isoelectric point (pI) oxidase enzyme (GOx), which allowed electrostatic interaction between outer layer film enzyme. architecture modified electrode GOx/(SiPy+Cl−/NiTsPc)5.5/FTO confirmed UV-Vis, FTIR, chronoamperometry techniques using different immobilization methods GOx. Among studied methods, higher variation current observed for formed mixed LbL films SiPy+Cl− NiTsPc immobilized drop coating. stability reproducibility verified when last containing coated with 0.2% Nafion® polymer. Under these conditions, linear response obtained in concentration range 0.2 to 1.6 mmol L−1 (R2 = 0.991) limit detection 0.022 L−1. proposed applied quantify two samples kombucha juices accuracy, allowing content healthy beverages be estimated.