An adhesive conducting electrode material based on commercial mesoporous titanium dioxide as a support for Horseradish peroxidase for bioelectrochemical applications

Abstract

An adhesive conducting electrode material containing of graphite, biocompatible ion exchange polymer nafion(®) and commercial mesoporous TiO2 impregnated with horseradish peroxidase (HRP) is prepared and characterized by amperometric, UV-vis and N2 sorption methods. The factors influencing the performance of the resulting biosensor are studied in detail. The optimal electrode material consists of 45% graphite, 50% impregnated HRP-TiO2 and 5% nafion(®). The optimum conditions for H2O2 reduction are an applied potential of -0.3 V and 0.1 mM hydroquinone. Sensitivity and limit of detection in the optimum conditions are 1 A M(-1) cm(-2) and 1 µM correspondingly. The N2 sorption results show that the pore volume of TiO2 decreases sharply upon adsorption of HRP. The preparation process of the proposed enzyme electrode is straightforward and potentially can be used for preparation of carbon paste electrodes for bioelectrochemical detections.

Amperometric Flow-Injection Analysis of Phenols Induced by Reactive Oxygen Species Generated under Daylight Irradiation of Titania Impregnated with Horseradish Peroxidase

“…The procedure for immobilizing HRP in mesoporous TiO 2 is reported in our previous work . The HRP-containing TiO 2 material is abbreviated as TiO 2 –HRP.…”

“…Next to its ability to generate reactive species to a certain extent, (mesoporous) TiO 2 has good biocompatibility and stability, , and therefore, it is a suitable material to immobilize biomolecules. , TiO 2 -based enzymatic sensors for the determination of phenolic compounds usually comprise tyrosinase, − peroxidase, − or laccase − enzymes. The working principle of these biosensors is based on the redox cycling of a biocatalytic oxidation product of an analyte and the following electrochemical reduction .…”

“…Herein, we use the inherited ability of TiO 2 to generate reactive oxygen species as a strategy to avoid adding H 2 O 2 in the solution during the detection of phenolic compounds. We implement this strategy in flow-injection analysis (FIA) because of comparatively short contact time of the sample with the electrode surface and enhanced mass transport in a wall-jet flow cell during amperometric measurements. , In contrast to our previous studies on analysis of phenols at a TiO 2 –HRP modified electrode, the sensor in this work can be used as prepared, and it does not require any H 2 O 2 neither for activation nor operation and it follows green chemistry principles of avoiding the use of reactive and harmful H 2 O 2 . This is advantageous to all previously described HRP-based sensors for phenols.…”

Electrochemical Biosensors Employing Natural and Artificial Heme Peroxidases on Semiconductors

“…Kumar et al reported that the introduction of such a nanoporous oxide layer enabled a direct electrochemical communication between adsorbed HRP and the electrode which was not observed on titanium alone [99]. Also for a mediated approach a significant increase in the hydrogen peroxide reduction by HRP was obtained when the enzyme was immobilized in a graphite composite with mesoporous TiO 2 rather than non-porous TiO 2 [100]. Alternative attempts to improve this communication included the incorporation of gold nanoparticles in between the enzyme and the TCO substrate [101].…”

Peroxidase enzymes as green catalysts for bioremediation and biotechnological applications: A review

“…and good sensitivity(Tatsuma et al, 1989). Recently,Rahemi et al (2016) coated Au electrodes by a composite mixture containing TiO 2 -entrapped HRP (50%), 45% of graphite and 5% nafion ® . The obtained enzyme electrode exhibited a hydrogen peroxide detection limit of 1 µM with an average sensitivity of 1 A M -1 cm -2 .…”