A Glucose Biosensor Based on Immobilization of Glucose Oxidase into 3D Macroporous TiO₂

Abstract

3D macroporous TiO 2 inverse opals have been derived from a sol-gel procedure using polystyrene colloidal crystals as templates. EDS and SEM showed a face-centered cubic (FCC) structure TiO 2 inverse opal was obtained. Glucose oxidase (GOx) was successfully immobilized on the surface of indium-tin oxide (ITO) electrode modified by TiO 2 inverse opal (TiO 2(IO) ). Electrochemical properties of GOx/TiO 2(IO) /ITO electrode were characterized by using the three electrodes system. The result of cyclic voltammetry showed that a couple of stable and well-defined redox peaks for the direct electron transfer of GOx in absence of glucose, and the redox peak height enhanced in presence of 0.1 mM glucose. Compare with the ordinary structured GOx/TiO 2 /ITO electrode, inverse opal structured GOx/ TiO 2(IO) /ITO electrode has a better respond to the glucose concentration change. Under optimized experimental conditions of solution pH 6.8 and detection potential at 0.30 V versus saturated calomel electrode (SCE), amperometric measurements were performed. The sensitivity and the detection limit of glucose detection was 151 mA cm À2 mM À1 and 0.02 mM at a signal-to-noise ratio of 3, respectively. The good response was due to the good biocompatibility of TiO 2 and the large effective surface of the three-dimensionally ordered macroporous structure.

Structure controlling and process scale-up in the fabrication of nanomaterials

“…For the preparation of the host-guest nanostructured composites, the intensification of mass transfer in the pores is very important because it is mainly the ratecontrolling step of the assembly process. Through electrochemical synthesis, low-temperature chemical reaction, sensor technology, layers of electrostatic selfassembly technology, and other physical chemical methods we successfully prepared magnetic composite microspheres, compound semiconductor fluorescent microspheres, flavor prolonged-release composite microspheres and fixed-peroxidase complex [27][28][29][30][31][32][33]. Figure 5 shows the process for the assembly of CdSe nanocrystals (NCs) in the pores of mesoporous silica (MS); the expanding of the pore size and the intensification of the mass transfer in the pores are very important for the assembly process.…”

Electrochemical performance and biosensor application of TiO2nanotube arrays with mesoporous structures constructed by chemical etching

“…Well aligned TiO 2 nanotube arrays (NTAs) were synthesized by Grimes via anodizing Ti sheets in HF solution [7]. The vertically oriented TiO 2 NTAs became a competing substrate in sensors, including gas sensor [8,9], COD sensor [10,11] and biosensor [12,13], due to the special architecture of nanotube arrays.…”

Planar Photonic Crystals Biosensor Applications of TiO2

“…TiO 2 nanotubes have been used to immobilizing proteins and enzymes in biomaterial and biosensor applications because of high sensitivity at the near-infrared (750 nm) and near-ultraviolet (400 nm) wavelengths [19]. It has been demonstrated that the large surface area, good chemical stability and nontoxicity of the TiO 2 have been achieved with dierent nanocomposite and 3D macroporous structures [20,21].…”