A glucose biosensor based on the polymerization of aniline induced by a bio-interphase of glucose oxidase and horseradish peroxidase

摘要

A novel glucose biosensor was developed based on a 4-amino thiophenol/Au nanoparticle/glucose oxidase (GOD)-horseradish peroxidase (HRP)/6-mercapto-1-hexanol-11-mercaptoundecanoic acid/Au electrode. The modified electrode could be used to detect glucose based on the polymerization of aniline induced by HRP and H2O2 which was produced by the reduction of O-2 accompanied by the oxidation of glucose into gluconic acid via GOD. With the increase of glucose, more H2O2 molecules were produced and then a growing number of polyaniline (PANI) molecules were formed on the modified electrode surface, which resulted in the decrease of peak current of Fe(CN)(6)(3-/4-) because the formed PANI hindered the electron transfer of Fe(CN) 6(3-/4-) toward the electrode surface. Based on the decrease of peak current of Fe(CN)(6)(3-/4-), the glucose concentration could be determined accurately and selectively. The resulted biosensor exhibited a wide linear range from 16.5 mM to 10.0 mM, a high sensitivity of 41.78 mu A mM(-1) cm(-2) and good selectivity. The glucose biosensor exhibits some advantages over the traditional GOD electrodes in terms of a close to zero applied potential. Moreover, the used electrode might be used as a H2O2 sensor due to its good electrocatalytic response for H2O2.