Preparation Of Titannium Dioxide Nanocomposite And Its Application In Electrochemical Enzyme Sensors

In recent years, biosensors have been widely used in chemical analysis, biomedical, clinicaldiagnostics, food detection, environmental monitoring and other fields. With the development of differentnano-materials and their application in the field of electrochemical enzyme biosensors, enzyme biosensorshave entered into a new stage. Nano-materials possess excellent performances in the field of optics,electricity and magnetism, due to its properties of small size effect, surface effect, macroscopic quantumtunneling effect and quantum size effect. While, in biosensors, the electrode materials were required thatthey should have good biocompatibility, excellent electrical conductivity, and large surface area. Theseproperties can accelerate electron transfer between the enzyme molecule and electrode, shorten responsetime, improve the sensitivity of the sensor, thereby, we can achieve the purpose of improving the biosensor.The titanium dioxide nano materials have these properties. In this work, we synthesized different titaniumdioxide composite materials with different methods, and also successfully prepared various novel enzymebiosensors by embedding method. The main contents are summarized as follows:1. TNTs–Au composite nanomaterial as a scaffold for the preparation of glucose oxidase sensorand its applicationFirstly, we successfully synthesized titania nanotubes (TNTs) using hydrothermal method; then goldnanoparticles were modified on the surface of TNTs by the traditional citrate reduction method; finally, theTNTs–Au composite nanomaterials were characterized by means of Fourier transform infraredspectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). After that, aglucose oxidase sensor was prepared using TNTs-Au composite nanomaterial as a scaffold. Theelectrochemical properties of this biosensor were studied by using Cyclic voltammetry and Differentialpulse voltammetry.2. TNTs–PTA–Au composite nanomaterial as a scaffold for the preparation of thiolated HRPbiosensors and its applicationFirstly, the gold nanoparticles were successfully modified on the surface of titania nanotubes withphosphotungstic acid (PTA) as a crosslinking agent by using photocatalysis method. Then the TNTs–PTA–Au composite nanomaterials were characterized by means of Fourier transform infraredspectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). HRP wasthiolated to obtain a tight interation between HRP and TNTs–PTA–Au composite by S–H chemical bond.Finally, a thiolated HRP biosensor was prepared based on TNTs–PTA–Au composite nanomaterial as ascaffold, and the biosensor was applied to the catalytic degradation of H2O2.3. GNPs–TNTs composite nanomaterial as a scaffold for the preparation of HRP biosensors andits applicationFirstly, we successfully synthesized graphene nanoplatelets–titania nanotube nanocomposite(GNPs–TNTs) by hydrothermal method; then the GNPs–TNTs nanocomposite were characterized bymeans of transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infraredspectroscopy (FT-IR); finally, a HRP biosensor was prepared using TNTs–PTA–Au composite nanomaterialas a scaffold. The electrochemical properties of this biosensor was studied by using Cyclic voltammetryand Chronoamperometry.