Spatial Architecture of Modified Carbon Nanotubes/Electrochemically Reduced Graphene Oxide Nanomaterial for Fast Electron Transfer. Application in Glucose Biosensor

Abstract

Electron transfer (ET) reactions in bioelectrocatalysis of enzymes at electrode surfaces require not only the efficient immobilization, but also highly conductive nanostructured platform, which allows for retaining its bioactivity and structural conformation. The novel architecture of spatially separated electrochemically reduced graphene oxide (ERGO) by multi‐walled carbon nanotubes functionalized with 4‐(pyrrole‐1‐yl) benzoic acid (MWCNT/PyBA) with the accurate porous structure could be an alternative for earlier approaches to the construction of bioelectrocatalytic systems with rapid diffusion of reagents from the solution to the enzyme molecule. The formation of ERGO/MWCNT/PyBA system was confirmed by electrochemical, spectroscopic and microscopic methods. The cyclic voltammetry experiments revealed that the presence of ERGO in the conductive material affects the electronic communication between the enzyme molecule and modified electrode surface greatly improving its ET properties resulting in a double increase of the heterogeneous ET rate constant value (ks=6.5 s−1). The fabricated glucose oxidase based biosensor sensitively detects glucose, therefore, ERGO/MWCNT/PyBA architecture could provide a novel and efficient platform for immobilization of redox enzymes.

Review—Carbon Nanotube-Based Electrochemical Glucose Biosensors

“…Oxygen as a natural redox mediator normally exist in the test solutions. 25 The oxygen-based biosensors are known as the firstgeneration biosensors. 26 The mechanism of signal production in O 2 -mediator biosensors can be described as follows: 19 Glucose GOx FAD gluconolactone GOx FADH…”

Review—Recent Advances in Carbon Nanomaterials as Electrochemical Biosensors

“…Through CV experiments, it was reported that the presence of ERGO in the conductive material increase the rate of electron transfer between the enzyme redox centre and the electrode surface. 362 Detection of DNA.-The detection of DNA plays a pivotal role in the diagnosis of various genetic or mutated medical ailments in the body. The electrochemical biosensor employed for detection of DNA has attracted the attention of researchers due to its low cost, high sensitivity and high selectivity for the detection of DNA sequences or mutated genes responsible for the various human diseases.…”