Immobilization of Invertase in DAD Type Polymers: Combination of Benzothiadiazole Acceptor Unit and 3,4-Ethylenedioxythiophene and Thiophene Donor Units

• Published in: Journal of macromolecular science. Part A, Pure and applied chemistry Vol. 48; no. 11; pp. 855 - 861
• Main Authors: Aydar, Sevda, Böyükbayram, A. Elif, Şendur, Merve, Toppare, Levent
• Format: Journal Article
• Language: English
• Published: Colchester Taylor & Francis Group 01.01.2011; Taylor & Francis
• Subjects: Applied sciences; Biological and medical sciences; Biotechnology; Copolymers; DAD monomers; electrochemical polymerization; Electrodes; enzyme immobilization; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Immobilization; Immobilization of enzymes and other molecules; Immobilization techniques; Invertase; Methods. Procedures. Technologies; Monomers; Optimization; Organic polymers; Physicochemistry of polymers; Polymers; Properties and characterization; sensor; Special properties (catalyst, reagent or carrier); Thiophenes; Ethylenedioxythiophene copolymer; Support; Enzyme; β-Fructofuranosidase; Invertase; Temperature effect; Immobilization; Thiophene copolymer; Experimental study; Benzothiadiazole copolymer; Glycosylases; electrochemical polymerization; Conjugated copolymer; Enzymatic activity; Storage stability; Glycosidases; Nitrogen heterocycle copolymer; Aromatic copolymer; pH; enzyme immobilization; Hydrolases; sensor; DAD monomers; Immobilized enzyme
• ISSN: 1060-1325; 1520-5738
• DOI: 10.1080/10601325.2011.614826

Conductive polymers with donor-acceptor-donor (DAD) type units; benzothiadiazole acceptor unit and 3,4-ethylenedioxythiophene (EDOT) and thiophene (Th) donor units, were investigated for immobilization of invertase. The polymers were prepared potentiodynamically from their monomers, M 1 (Th-benzothiadiazole-Th), M 2 (EDOT-benzothiadiazole-EDOT), M 3 (Th-benzothiadiazole-EDOT) and a copolymer, which is a homolog to homopolymer of M 3 , was prepared from M 1 and M 2 . Invertase was trapped between a two layer-composite; DAD polymer and polypyrrole. The characterization of immobilized invertase was performed using a spectrophotometric method at 540 nm. Kinetic parameters, V max , maximum reaction rate and K m , Michaelis-Menten constant values of immobilized invertase in DAD type homopolymer (P 3 ), 0.95 μmol min −1 and 22.7 mM, respectively, are found between those of homopolymers P 1 and P 2 and are better than the copolymer. Polymers and copolymers exhibited a broad optimal temperature profile between 30 and 50°C compared to the free enzyme. Optimum pH (5.0) is the same as for free invertase. The electrodes were found to be stable with 100% activity during one day for 40 consecutive measurements. As to the self-life, 25% of the initial activity was lost in the first ten days, then the electrodes were stable with 75% activity for a 40 day storage at 4°C.