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

The use of enzymatically modified electrodes for the detection of glucose or other nonelectrochemically active analytes is becoming increasingly common. Direct heterogeneous electron transfer to glucose oxidase has been shown to be kinetically slow, 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 multiwalled carbon nanotubes (CNTs) demonstrate fast heterogeneous electron transfer kinetics as compared with that found for traditional electrodes. Incorporating CNTs into the assembly of electrochemical glucose sensors, therefore, affords the possibility of facile direct electron transfer to glucose oxidase and a more direct determination of glucose. This chapter will describe 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.