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

Abstract

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

Exploring Deposition Techniques and Supramolecular Arrangement in Thin Films for Sensor Applications

“…The oxidation performance depended on the metal centre, with the higher oxidation achieved by CoPc [164]. The LbL combination of Pc and carbon-derived materials is also promising in sensing applications [164,167]. Besides, the incorporation of Pc in LbL films is also explored for the development of biosensors [167,168].…”

“…The LbL combination of Pc and carbon-derived materials is also promising in sensing applications [164,167]. Besides, the incorporation of Pc in LbL films is also explored for the development of biosensors [167,168].…”

Facile Electrochemical Biosensing Platform Based on Laser Induced Graphene/Laccase Electrode for the Effective Determination of Gallic Acid

“…The excellent hydrophilicity and high oxygen content of LIG was beneficial for the glutaraldehyde-mediated covalent immobilization of laccase on the surface of LIG electrode to construct an amperometric enzyme biosensor for GA. The immobilization of the enzymes on the electrode surfaces is an important step in the preparation of the biosensor, as it preserves the enzymatic activity and designs efficient pathways for electron transfer between the immobilized enzyme and the electrode surface [34]. The direct cross-linking of laccase makes the electrode modification process very convenient, indicating that the LIG/Lac-based GA sensor possess a highly valuable application.…”

Heparin-stabilized gold nanoparticles embedded in graphene for the electrochemical determination of esculetin

“…11,17–19 Modified electrodes are analytical tools that can be obtained by immobilizing a variety of materials (inorganic and organic) on the substrate surface with the aim of improving the sensitivity and selectivity of the analytical method. 20–23 In addition, the miniaturization and portability of the equipment allows for rapid on site analysis and disseminates the applicability of electroanalytical methods to different matrices. 24–27…”