Thi rd genera tion glucose biosensor using covalen tly immobilized glucose oxidase onto poly(Aminothiophenol)/ carbon nanotube s electro de

The efforts to dev elop and im prove glucose sensors have been made near five decades since Clark and Lyons reported the first enzy me electrode in ۱۹۶۲. For the first time, Up dike and Hicks was immobilized glucose oxidase (GOX) in a gel on an oxygen electrode and m easured glucose concentration in bi ological flu ids. One of the mo st challenging aspect s in the develop ment of highly sensiti ve glucose sensor is the selectio n of a suitable matrix for GOX immobilization, w ith high mechanical strength, excellent conductivit y and ant ifouling properties. Theref ore, the de velopment of high sen sitive, low-cost, relia ble glucose sensors having an excellent selectivity has beenthe subject of con cern for decades, not only in medical science bu t also in the food industries [۱-۳]. In the p resent study, an elect ropolymeri zed film of ۴-Aminothiophenol w as prepare d on the surface of a GC electrode mo dified with multi-walled carbon nanotubes, (CNTs) in ۰.۱۰ M HCl in methanol. Cyclic voltammetry was used for both theelectrochemical synthesis of poly-(۴-Aminothio phenol) o n the surfa ce of a m ulti-walled carbon nanotubes modified glassy carbon electrode (GCE ), and characterisation of the polymers deposited on t he GCE. The sy nergisitc effect of the high activ e surface area of both the conducting polymer and carbon nanotubes gave rise to a remarkable improv ement in the electrocatalytic properties of the biosensor. T he heterogeneous elect ron transfer rate constant was ۳.۷ s-۱ in pH ۷, indicating gre at facilitation of th e electron transfer between GOx and poly(۴-Aminothiophenol)/MWNTs adsorbed on the electrode surface. The modified GCE biosensor was ex hibited two linear responses to gl ucose in th concentration range of ۱۰-۴۵۰ ȝM, with correlation coefficients of ۰.۹ ۸, good sensitivity (۰.۰۴ ȝA/ȝM), repeatability (RSD value of ۱.۶%)and long-term stabilit y. This is a simple and easy ap proach for the fabrication of enzyme electrodes for the selective det ection of glucose in a biological sample. T he good perfor mance of this glucose sensor could be attributed to the stability of poly(۴-Aminothiophenol)/MWCNT a nd this opens up new horizons in the field of functio nalized MWCN T based glucose sen sor related researches.

کلیدواژه ها:

Electropolymerization ، Glucose biosensor ، carbon nanotubes