(376f) Layer-by-Layer Electrostatic Assembly of Carbon Nanotube Based Glucose Sensors

Glucose biosensors were fabricated by alternate immersion of gold electrodes in solutions of a positively charged redox polymer, poly[(vinylpyridine)Os(bipyridyl)2Cl2+/3+] and a negatively charged enzyme, glucose oxidase (GOX) or a GOX solution containing single-walled carbon nanotubes (SWNTs). The layer-by-layer assembly of the multilayer films were characterized by UV-vis spectroscopy and cyclic voltammetry, while characterization of the single-walled nanotubes was performed with transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. When the glucose oxidase solution contained single-walled carbon nanotubes (SWNTs) the oxidation peak currents during cyclic voltammetry increased 1.4 - 4.0 times as compared to films without SWNTs. Similarly the glucose electro-oxidation current also increased (6-17 times) when SWNTs were present. By varying the number of multilayers, the sensitivity of the sensors could be controlled.