新型光电化学生物传感器中若干关键问题的研究

Photoelectrochemical biosensor (PEC biosensor) is a newly appeared biosensor which developed on the basis of combining photoelectrochemical process with electrochemical biosensor. In photoelectrochemical biosensor system, light is employed as excitation signal and current is utilized as detection signal. Because of the total separation of excitation signal and detection signal, this technique possesses potentially higher sensitivity because of the reduced background signals. Accordingly, photoelectrochemical biosensor, as an ideal and novel sensing mechanism, has received more and more attention and become a research focus. However, in most previously reported literatures, only single photoelectric conversion material was employed in PEC biosensor system. As a result, the energy of light source can not be fully utilized because different photoelectric conversion materials have different energy band gaps and each photoelectric conversion material possess its own optimal light absorption band. Based on the situation mentioned above, photoelectric conversion composite materials, which consist of photoelectric conversion materials with different energy band gaps, were proposed to adopt in PEC biosensor system to solve this problem and significantly improve the performance of PEC biosensor. Specifically, this project is mainly focused on the following key issues: (1) preparation of functional nanomaterials and quantum dots with high photoelectric conversion efficiency; (2) construction and mechanism of new type of photoelectrochemical biosensor; (3) modification and assembly of photoelectrochemical biosensing electrode. Believably, new breakthroughs will be produced on the aspects of photoelectric conversion efficiency of functional materials and detection performance of photoelectrochemical biosensor.

光电化学生物传感是以光电化学过程与电化学生物传感器相结合为基础发展起来的新一代传感器。它以光为激发信号，而电信号则作为检测信号。由于采用了两种不同形式的激发和检测信号，使得该技术背景信号低，具有更高的灵敏度。因此作为一种理想的新型传感机制，它已成为当前研究热点之一。但在已有的光电化学生物传感器中大都采用单一的光电转换材料，受光电转换材料能带宽度的限制，每种光电转换材料均对应有最佳的吸光波段，因此不能充分利用光源的能量。为此，本项目提出用具有不同能隙宽度的光电转换材料组成光电转换复合材料，使之能够对白光等连续光源中各个波段的光均充分的利用，从而显著提高光电信号和光电化学生物传感器性能。本项目主要围绕（1）高光电转换功能纳米材料及量子点的制备；（2）新型光电化学生物传感方式与机理探索；（3）光电化学生物传感电极的修饰与组装等关键问题进行基础研究，争取有所新突破。

本项目按照计划书规划顺利完成研究任务，以通讯作者发表SCI论文29篇，其中Nature指数刊物论文12篇，影响影子大于10论文3篇。代表性论文：Chem.Soc.Rev. 1篇，Angew. Chem. Int. Ed. 1篇，Anal. Chem.5篇，Chem.Commun. 4篇，Chem. Sci. 1篇, Biosensors and Bioelectronics 3篇， Journal of Materials Chemistry A 3篇；专利1件。毕业博士生5名，硕士生1名。达到了预期研究目标。 主要成果如下：.成功制备了一批具有各个能带宽度（如~3.2 eV、~2.4 eV、~1.4 eV）的光电复合纳米材料，例如TiO2/CdS/CdSe二元共敏化光电材料、尺寸不同的CdTe 量子点共敏化TiO2/CdS:Mn 杂合物、SiO2@Ab2信号放大和CdS:Mn/CdTe共敏化TiO2纳米管、CdSeTe合金量子点和SiO2@Au纳米复合物之间高效的激子能量转移复合物、CdSe@ZnS核壳量子点敏化TiO2NWs /Au 纳米复合物、CdS:Mn@Ru(bpy)2(dcbpy)纳米复合物等，并将他们作为光电活性材料，显著提高了光电化学系统的光电转换效率。在此基础上，设计了多种新颖的信号放大元件，采用标记性策略构建了高灵敏的光电化学免疫传感、DNA传感以及适配体传感。.光电免疫分析方法通常以光电阳极为传感电极，但是，该方法在实际样品分析中具有抗干扰能力差的固有弱点。以光电阴极为基础的光电免疫分析方法可以有效地避免了实际样品中测定干扰的问题。我们设计了由光电阳极和光电阴极组成、以光电阴极作为免疫传感电极，分析生物标志物的新颖光电免疫分析方法。所设计的分析方法具有二个明显的优点：第一，由于在光阴极上进行生物识别和传感，所以，在检测实际生物样品时，阴极传感具有良好的抗干扰能力。第二，由于引入了光阳极，提高了检测目标分析物Ag的光电流和检测限。.设计构建了新型光电生物燃料电池，将氮掺杂3D石墨烯作为阳极基地电极种植和生长微生物。同时，对可见光有响应的p-型CuS纳米材料作为光敏化剂 用于制备生物燃料电池的阴极。该光助微生物燃料电池既能从燃料又能从光能中获得电能，在电池中同时实现了二种能量的转变，功率输出达到2607 mW m-2，显示出良好的应用潜力。