基于金三维纳米阵列电极的AFB1免疫传感体系构建和电化学机制研究

There are many shortcomings in the present analysis method, such as lack of sensitivity, time consuming, and too complicated to handle. The AFB1 detecting system have been suggested in this project by taking the combining advantages of gold 3D brush nanoelectrode ensembles （3DBNEEs）and label free electrochemical immunosensor..In the study of 3DBNEEs, the dimension controllable 3DBNEEs with high stability and reliability will be produced by effective combination of the technologies including template synthesis, electroless deposition and controllable etching. The interactional mode of the diffusion layer between the electrode element and the kinetic character were studied in 3DBNEEs system with different structures and dimensions. In the study of biosenor, the fixation method of the antibody (or antigen) on electrode and the influencing factor will be studied. The influence rule of the biological molecule recognition membrane on interfacial capacitance, electrode process and kinetic parameters of electrochemical probes will be revealed. The AC impedance label free immune biosensing technology system for the the detection of Aflatoxin B1 based on 3D gold electrode Ensembles will be constructed in order to achieve the purpose of AFB1 detection which possess the advantages of time saving and sensitivity. The study and application of this project will not only provide scientific basis for the application of 3DBNEEs in immune biosensor, but also the new technology approach for AFB1 practical detection. In addition, the project has very important significance in the field of guaranteeing civil food safety. Further more, this project will have reference meaning for fungus toxins analysing technology based on electrochemical biosensor.

针对现有黄曲霉毒素B1（AFB1）分析方法灵敏度低、速度慢、操作步骤复杂等问题，提出结合金刷式三维纳米阵列电极（3DBNEEs）和无标记电化学免疫法的优势，构建AFB1检测体系。.在电极方面，结合模板法、化学沉积法和可控刻蚀技术，制备尺寸可控、性能稳定3DBNEEs。研究不同结构和尺寸的3DBNEEs体系中单个电极间扩散层的相互作用方式，及3DBNEEs体系的动力学特征。在传感器方面，重点研究抗体(抗原)在电极上的有效固定方法，探索抗体（抗原）固定的影响因素，揭示不同尺寸电极的生物分子识别膜对界面层电容、电化学探针的电极过程和动力学参数的影响规律。构建基于金3DBNEEs交流阻抗型AFB1无标记免疫传感检测技术体系，实现AFB1快速灵敏检测。本项的研究和实施不仅可为AFB1实际检测提供新的技术途径，也为3DBNEEs在免疫传感器中的应用提供科学依据，对保障国民食品安全与健康具有重要意义。

针对现有黄曲霉毒素B1（AFB1）分析方法灵敏度低、速度慢、操作步骤复杂等问题，本项目结合金三维纳米阵列电极（3DNEEs）、蛋白A (SpA)定向作用及无标记阻抗型免疫传感器的优势，构建了快速灵敏的AFB1电化学免疫传感检测体系。.在电极方面，结合模板法、化学沉积法和可控刻蚀技术，制备尺寸可控、性能稳定的三维纳米棒阵列电极（3DBNEEs）和三维纳米管阵列电极（3DTNEEs）。系统地研究了不同尺寸的3DBNEEs循环伏安行为和阻抗谱，研究了纳米柱直径、长径比和间距对3DBNEEs扩散形式的影响规律。通过阻抗谱拟合分析，得出电极活性面积、传荷阻抗以及表观速率常数等参数。针对3DTNEEs还研究了管内电流随管深度的变化规律。.在传感器方面，构建了基于聚邻苯二胺修饰金电极（PoPD/Au）的无标记阻抗型IgG免疫传感器，基于蛋白A (SpA)定向的PoPD/3DBNEEs的AFB1免疫传感器，基于半胱胺自组装膜修饰金3DBNEEs/AFB1免疫传感器和基于SPA直接修饰3DTNEEs（3DBNEEs）的AFB1免疫传感器。对免疫传感器的组装过程中可能发生的反应及原理进行了分析，并对传感器组装不同阶段进行了电化学表征。重点研究了AFB1抗体在电极上的有效固定方法。对传感器的测量条件如电化学探针、极化电位、传感器的再生、稳定性等因素进行了研究。构建了分子识别膜模型，设计了等效电路，对测定的阻抗谱进行了拟合和分析，得到了传感体系相应的参数和AFB1浓度。.本项目所构建的基于金3DBNEEs或（3DTNEEs）和SpA定向的无标记阻抗型AFB1免疫传感检测技术体系，比其他研究者构建的无标记阻抗型AFB1免疫传感器具有较明显优势。线性范围较宽，检测限低于欧盟规定的最低限量标准2ng/g，实现了AFB1快速灵敏检测。本项目的研究和实施不仅可为AFB1实际检测提供新的技术途径，也为3DNEEs在免疫传感器中的应用提供科学依据，对保障国民食品安全与健康具有重要意义。.