本论文将TiO2纳米粒子和弱聚电解质在电极表面构筑层层组装（LBL）薄膜，实现了电活性探针在薄膜电极上的pH敏感的“开关”效应，并用来调控生物电催化。还将肌红蛋白（Mb）和胶原蛋白（collagen）在电极上构筑LBL薄膜，实现了薄膜中Mb的直接电化学和对某些底物的电催化还原。全文共分为三章。第一章 前言简述了氧化还原酶和蛋白质的电化学研究的意义及研究现状，并对本论文涉及到的几种氧化还原酶和蛋白质的结构和功能做了简单介绍。简述了LBL技术和氧化还原蛋白质在LBL薄膜上的直接电化学。介绍了TiO2纳米粒子的性质及应用。简要综述了对环境中不同的物理和化学刺激因素具有响应的可开关的薄膜以及环境响应性薄膜在可调控的生物电催化中的应用。第二章 基于TiO2纳米粒子和弱聚电解质PAH的层层组装薄膜的具有pH开关性质的生物电催化采用带有相反电荷的TiO2纳米粒子和弱聚电解质聚烯丙基氯化铵（PAH）作为成膜材料，在合适的组装pH条件下，在热解石墨（PG）电极表面构筑{PAH/TiO2}n LBL薄膜。采用循环伏安法（CV）考察了不同电荷的电活性探针在该薄膜电极上的对pH敏感的通透性。薄膜电极对K3Fe(CN)6探针表现出pH敏感的开关性质，可用于调控以K3Fe(CN)6为媒介体的HRP对底物H2O2的电化学催化还原。通过一系列对比实验对该体系pH开关的机理进行了探讨。第三章 胶原蛋白和肌红蛋白的层层组装薄膜及其电化学研究将氧化还原蛋白质Mb和胶原蛋白在不同的固体基底表面进行层层组装，构筑了{collagen/Mb}n LBL薄膜。电化学惰性的胶原蛋白在这里作为一种生物相容性好的基质和成膜材料来实现Mb在电极上的固定，成功实现了Mb在薄膜电极上的直接电化学及对O2和H2O2的电催化还原。采用各种方法表征了{collagen/Mb}n LBL薄膜的组装过程，对不同组装条件下胶原蛋白和Mb之间层层组装的成膜驱动力与相互作用做了探讨。

In this dissertation, TiO2 nanoparticles and weak polyelectrolytes were assembled into layer-by-layer assembly (LBL) films on electrodes. The LBL films demonstrated pH-sensitive “on-off” property toward electroactive probes and this pH-dependent “on-off” switching behavior could be used to control the bioelectrocatalysis. Myoglobin (Mb) and collagen was assembled into {collagen/Mb}n LBL films on PG electrodes. The direct electrochemistry of Mb in the films was realized and was used to electrocatalyze various substrates. Chapter 1 ForewordA brief introduction of the significance on investigation of electrochemistry of redox enzymes and proteins were described, and the structure and function of three enzymes or proteins utilized in this work were introduced. The introduction of LBL technique and the direct electrochemistry of redox proteins in LBL films were presented. The characters and application of TiO2 nanoparticles were also presented. Switchable or signal-triggered films sensitive to different external physical or chemical stimuli and their application in switchable bioelectroanalysis were reviewed. Chapter 2 pH-sensitive switching permeation of layer-by-layer films assembled with TiO2 nanoparticles and poly(allylamine hydrochloride) toward electroactive probes and its application in bioelectrocatalysisOppositely charged TiO2 nanoparticles and weak polyelectrolyte poly(allylamine hydrochloride (PAH) were selected as the building blocks to assemble {PAH/TiO2}n LBL films on solid surfaces under appropriate pH conditions. The pH-sensitive switching behavior of {PAH/TiO2}n LBL films on electrodes toward differently charged electroactive probes were investigated by cyclic voltammetric (CV) method. The {PAH/TiO2}n films demonstrated a pH-sensitive on-off property toward K3Fe(CN)6 and this pH-sensitive switching property was further used to control or modulate the electrocatalytic reduction of H2O2 by HRP with Fe(CN)63- as the mediator. The mechanism of the pH-dependent permeability of the films toward the probes was also investigated.Chapter 3 Layer-by-layer assembly of collagen and electroactive myoglobin and their electrochemistry studyRedox protein Mb and collagen were successfully assembled into {collagen/Mb}n LBL films on different solid surfaces. The electroactive inert collagen was used as a biocompatible matrix to immobilized Mb on electrodes. Mb in the {collagen/Mb}n films showed good direct electrochemistry and electrocatalytic reactivity toward O2 and H2O2. The formation of {collagen/Mb}n LBL films were monitored or confirmed by different methods and the driving forces of the assembly of the films under different conditions were also discussed.