Bioelectrochemistry Studies Based On Functional Halloysite Nanomaterials

Such biological macromolecules redox enzymes and proteins direct biological electrochemical caused extensive concern of the scientific fields. Because its not only the ideal model of research on biological redox process thermodynamic and kinetics, but also offerred potential prospects for the development of high selectivity, high sensitivity and high stability of bioelectricity catalysis biosensor. However, due to the redox active center deeply embedded in the protein inner shell, most redox protein are difficult to achieve the direct electron transfer in traditional electrode. In this work, halloysite nanotubes and some new nanomaterials used as biological carrier and molecular wires for constructting the biological molecules/micro-nano material interface on conductive basal, providing a suitable biological microenvironment for redox proteins, enzymes and other biological macromolecules, realizing their direct electron transfer and obtain excellent bioelectricity catalytic performance finally. The study for deep understanding the electron-transfer reactions mechanism of protein, enzyme and biological macromolecules in life body as well as the development of new biosensors, new biofuel cell biological electronic devices provide valuable theoretical and practical reference. This thesis main research work are as follows:1. Direct electrochemistry and electrocatalysis of horseradish peroxidase based on halloysite nanotubes/chitosan nanocomposite film.Using a new kind of silicate nanotube material as the carrier, providing a suitable biomicroenvironment for HRP, promoting its redox active center Fe(Ⅲ)/Fe(Ⅱ) fast electron transfer, at the same time use of HNTs/Chi nanocomposite film improve the stability of the modified electrodes. Through the spectrum, ac impedance, cyclic voltammetry, current-time methods show that the properties of film is good; HRP keeps good natural conformation and show a good electrochemical behavior in nanocomposite film; HNTs/Chi composite film realized the direct electron transfer of HRP and improving the electrochemical catalysis sensitivity for hydrogen peroxide.2. The preparation of gold nanoparticles-halloysite nanotube nanocomposite materials and its application in none enzyme electrochemical sensor. TEM, Zeta, UV characterization illustrate composite materials successfully prepared; electrochemical CV and EIS analysis shows that the existence of gold nanoparticles improved modified electrode surface activity; i-t analysis show that the existence of gold nanoparticles enhance the modified electrodes catalyzed sensitivity to hydrogen peroxide. The preparation of none enzyme sensor can be used linear detection of hydrogen peroxide and avoid common enzyme sensor deactivation characteristics.3. With TEOS and F127 as raw material soft-template synthesis carbon silicon nanomaterials, then use HF to remove silicon frame get mesoporous carbon at last. TEM, BET characterization of synthesis of mesoporous carbon that are highly two-dimensional highly order structure, high surface area (2066 m²/g), high pore volume (1.64 cm³/g) and narrow pore size distribution. Meanwhile, Raman analysis shows that the synthesis of mesoporous carbon more edge sites, so has large defects of activity, with mesoporous carbon enhanced the hemin adsorption on the electrode surface and promoted the its electron transmission rate for 2.7s^-1 , enhanced the sensitivity of modified electrodes to hydrogen peroxide detection.