Enzyme immobilization in biosensor constructions: self-assembled monolayers of calixarenes containing thiols

Abstract

Herein, an amperometric glucose oxidase (GOx) biosensor is presented using calixarenes as an immobilization matrix of the biomolecule. Firstly, thiol-containing calixarenes (Calix-SH) were synthesized, then self-assembled monolayers (SAMs) of Calix-SH on a gold surface were formed and hydroxyl groups of Calix-SH were activated using 1,1 0 -carbonyldiimidazole (CDI) chemistry. To test the usability of Calix-SH modified surfaces as a biosensor, glucose oxidase was used as a model biological component. After optimization of preparation and working conditions, our results indicate that the Calix-SH/GOx biosensor has a linear range in the range 0.1-1.0 mM (LOD: 0.015 mM) for glucose with a 25 s response time. Finally, the application of the biosensor was examined to detect glucose in real samples.The glucose amounts were calculated as 19.460 AE 0.521 and 31.647 AE 2.125 mM in coke and fizzy drink (with orange), respectively. To confirm the reliability of the Calix-SH/GOx biosensor, the calculated glucose concentrations which were analyzed by the Calix-SH/GOx biosensor were compared to conventional spectrophotometric glucose kits. The glucose amounts in coke and fizzy drink were calculated as 18.509 AE 0.732 mM and 31.579 AE 4.466 mM, respectively.

Lithiation and Delithiation Mechanisms of Gold Thin Film Model Anodes for Lithium Ion Batteries: Electrochemical Characterization

“…Interfacial electrochemistry has often used Gold (Au) substrates as model systems for various aspects of surface science problems, from metal-organic interfaces, such as for example thiol selfassembled monolayers [1,2], (bio)-sensor applications [3][4][5][6] or fundamental oxidation studies [7]. The high inertness and ease of sample preparation by flame annealing renders Au an appealing model system for electrochemical studies.…”

Ferrocene-Functionalized 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline: A Novel Design in Conducting Polymer-Based Electrochemical Biosensors

“…Figure 3a shows the co-polymer-modified surfaces before the immobilization of GOx and SNS-NH 2 /SNS-NH 2 -Fc/GOx modified surfaces can be seen in Figure 3b . GOx (β-D-glucose: oxygen 1-oxidoreductase, EC 1.1.3.4) contains two identical subunits, which are flavine adenine dinucleotide (FAD) cofactor bound to the polypeptide chains [ 31 , 32 ]. Due to the FAD centers, GOx and polymeric matrix exhibit fluorescent properties; hence it is possible to monitor biomolecule immobilization via fluorescence microscopy.…”

Influence of poly(acrylic acid) grafting density on switchable protein adsorption/desorption of poly(2‐methyl‐2‐oxazoline)/poly(acrylic acid) mixed brushes

“…Controlled protein adsorption on the surface of materials has been the topic of great interest in biomedical and biotechnological fields over the years . For instance, protein adsorption on the surface of biosensors can not only limit the accuracy of analysis but reduce the useful life of equipment as well, which is uncontrolled and nondesirable . Conversely, the adsorption of proteins is necessary for drug delivery, cell adhesion and growth .…”