Studies On Preparation Of Prussian Blue/ Titanium Dioxide Nanotube Arrays Electrode And Its Application In The Biosensors

As an electrochemical biosensor, glucose biosensor takes advantage of high-specificity of glucose oxidase enzymatic reaction and high-sensitivity of Electrochemical signal detection. Nanoparticles have large specific surface area and high biocompatibility, and nanoparticles can also promote electron transfer rate between enzyme and electrode. We introduced nanoparticles to increase adsorptive capacity and stability of glucose oxidase (GOD). With this method, catalytic activity of enzyme, response speed of electrode and detection sensitivity can be improved.In chapter 1, we give a review for the structure, preparation method, and application of Prussian blue and nanomaterials. In this chapter, we also described fixing method of biological molecules and their application in glucose sensorsIn chapter 2, the application of PB modified TiO2 nanotube arrays in H2O2 sensing was studied. First, highly ordered TINT arrays electrodes were prepared by anodization, and then AuNPs was assembled on TiNTs via surface modification. By this method, the electrical conductivity of the TiNT arrays electrodes was improved effectively. PB-AuNPs/TiNT modified electrodes were prepared by illuminating. The results of FT-IR, XPS, XRD and electrochemical measurement showed that the PB which is decorated on AuNPs/TiNT arrays electrodes. The resulting electrode showed good electrochemical sensing response to H2O2 with the detection linear range of 1.1μmol/L to 6.7 mmol/L and detection limit was 0.10 μmol/L.In chapter 3, Glucose amperometric biosenser was developed about double enzyme modification based on PB/TiO2 nanotube arrays electrode. Glucose oxidase and horseradish peroxidase were fixed on the PB-AuNPs/TiNT by electrochemical polymerization of o-phenylendiamineThe FT-IR results confirmed that o-phenylendiamine(OPD)and double enzyme were assembled successfully. Electrochemistry results showed that direct transfer of electrons take out between active center of enzyme and electrode surface. Simultaneously, enzymes molecules fixed on the electrode keep their biological activity and electrocatalytic activity. Based on the study of dual-enzyme glucose sensing, the resultant composite electrode exhibit the detection linear range of 0.03 mmol/L to 0.30 mmol/L for glucose sensing on GOD-HRP-OPD-PB-AuNPs/TiNT electrodes, with the detection limit of 10 μmol/L(S/D=3), and the sensitivity of 0.021·mA·L·cm-2·mmnol-1. When AuNPs were introduced to electrochemical polymerization, the detection linear range is from 0.03 mmol/L to 0.50 mmol/L for glucose sensing on AuNPs-GOD-HRP-OPD-PB-AuNPs/TiNT electrodes, with the detection limit of 1.0μmol/L, and the sensitivity of 0.15-mA-cm-2·mmol-1·L. It can be concluded that, with the introduction of AuNPs the dual-enzyme glucose sensor exhibit a higher sensitivity and lower grade detection limits. Moreover, as poly o-phenylendiamine is one of non-conductive polymers, this system has high anti-interference ability to common electroactive material such as ascorbic acid, uric acid and acetaminophen and so on.