CTAB modified dellite: A novel support for enzyme immobilization in bio-based electrochemical detection and its in vitro antimicrobial activity

A novel support material for enzyme immobilization based on cetyltrimethylammonium bromide modified Dellite (CTAB-Del) was successfully synthesized and used to manufacture pyranose oxidase (PyOx) biosensors (CTAB-Del/PyOx). The intercalation of CTAB into Dellite was confirmed by FTIR, XRD and TGA techniques. PyOx was immobilized onto the glassy carbon electrode, via glutaraldehyde crosslinking, by using CTAB-Del as a support. In order to test the analytical performance of CTAB-Del/PyOx biosensors, chronoamperometric measurements were carried out using three electrodes configurations, at a constant potential of 0.7 V in working buffer, under stirring, with successive addition of glucose. The linear response for CTAB-Del/PyOx biosensor ranged from 0.01 to 0.50 mM with an equation of y=4.42x+0.004 (R-2=0.998), and the limit of detection for glucose was calculated to be 0.081 pM (S/N = 3). In order to confirm its practical use, the CTAB-Del/PyOx biosensor was also applied for glucose measurement in various beverages. In addition, the antimicrobial activities of Del and CTAB-Del were screened in vitro by means of the disc diffusion susceptibility test, selecting a yeast, three different Gram-positive, and five different Gram-negative bacteria. The obtained results showed a moderate antibacterial activity of CTAB-Del against Gram-positive bacteria. (C) 2016 Elsevier B.V. All rights reserved.