Layer-by-Layer Assembly of Glucose Oxidase on Carbon Nanotube Modified Electrodes

Abstract

The use of enzymatically modified electrodes for the detection of glucose or other non-electrochemically active analytes is becoming increasingly common. Direct heterogeneous electron transfer to glucose oxidase has been shown to be kinetically difficult, which is why electron transfer mediators or indirect detection is usually used for monitoring glucose with electrochemical sensors. It has been found, however, that electrodes modified with single or multi-walled carbon nanotubes (CNTs) demonstrate fast heterogeneous electron transfer kinetics as compared to that found for traditional electrodes. Incorporating CNTs into the assembly of electrochemical glucose sensors, therefore, affords the possibility of facile electron transfer to glucose oxidase, and a more direct determination of glucose. This chapter describes the methods used to use CNTs in a layer-by-layer structure along with glucose oxidase to produce an enzymatically modified electrode with high turnover rates, increased stability and shelf-life.

Enhanced thermostability and catalytic efficiency of glucose oxidase in Pichia Pastoris

“…Glucose oxidase (GOD, EC.1.1.3.4) is a bisubstrate enzyme that oxidizes β-D -glucose via molecular oxygen and produces d-glucono-δ-lactone and hydrogen peroxide (H 2 O 2 ) [1]. The catalytic characteristics of GOD meet the requirements of different fields, and the enzyme has been widely used in food manufacturing [2], clinical diagnosis and multiple other fields, for example, decreasing the glucose concentration to produce a reduced-alcohol wine in the beverage industry [3]; producing an enzymatically modified electrode with high turnover rates, stability and shelf-life [4]; loading on reagent-free colorimetric biosensors for glucose detection [5]; elevating tomato antiherbivore defenses [6]; improving the growth performance, gut health and cecal microbiota of broiler chickens [7]; producing sodium gluconate [8] and so on. GOD plays an increasingly important role in various fields, especially research on substitutes for antibiotics and agricultural and veterinary drugs.…”