A Novel Electrochemical Glucose Biosensor Based on TiO2 Nanotube Arrays
thesisposted on 28.11.2018 by Nasim Farajpour
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Diabetes mellitus is the most common endocrine disorder of carbohydrate metabolism. It is a leading cause of morbidity and mortality and a major health problem. In this study, we developed two high performance glucose biosensors based on the immobilization of glucose oxidase (GOx) onto TiO2 nanotubes (TiNTs) arrays modified by Prussian blue (PB) and Au and AgO NPs. Electrochemical Anodization followed by Ag electroplating process in the same electrolyte was used for synthesizing of Ag oxide deposited Titanium nanotubes. Deposition of Prussian blue (PB) particles was performed from an acidic ferricyanide solution. The surface morphology and elemental composition of the two fabricated biosesnors were investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) which exhibits successful deposition of Au and AgO nanoparticles as well as PB nanocrystals. Cyclic Voltammetry and Chronoamperometry were used to investigate the performance of the modified electrochemical biosensors. Findings reveal that the GOx/PB/Au/TiO2 NTs electrode considerably enhanced the current response signal in glucose solution in compared to absent of glucose. In a same way, the GOx/PB/Ag/TiO2 NTs electrode noticeably improved the current response signal in glucose solution in compared to absent of glucose. In addition, both electrodes exhibit significant increase in the current response signal as compared with the GOx/TNTs electrode. The results show that the developed electrochemical biosensors display good stability, low detection limit as well as high reproducibility for the determination of glucose. Under the optimized conditions, the Amperometric response shows a linear dependence on the concentration of Glucose with a detection limit down to 4.91 µM and 58.7 µM, sensitivity of 185.1 µA and 29.1 µM for Au NPs and AgO NPs modified biosensors respectively. Therefore, the reported study proposed a novel method for developing an enzymatic electrochemical glucose biosensor based on deposition of AgO NPs and PB nanocrystals on Titanium NTs.