低维TMDs多元材料的成分调控与光电转换以及生物特异性分析

Herein, to overcome the disadvantages of low efficiency for visible light utilization, easy combination of photo-induced charges, low photoelectric conversion efficiency of binary low dimensional transition metal dichalcogenide (TMDs) photoactive materials, we propose to synthesize high quality low dimensional TMDs multinary materials with low-toxicity and high visible light absorption via chemical doping and alloying strategies, and construct heterostructures with oxide/sulfide semiconductors and noble metals nanoparticles/carbon nanostructures to proliferate photoelectric conversion efficiency. The project aims at developing high-performances heterostructured photoelectrodes for efficient photoelectrochemical recognition and specific detection of biomacromolecules, based on recent research hotspots on low dimensional materials, as well as imperious demands on biomedical detection, diagnosis and forecast. The TMDs/oxide (or sulfide) heterostructure is designed to increase driving force for photo-induced charges separation and inhibit electron-hole recombination, while combination of noble metals nanoparticles (or carbon nanostructures) in heterostructures will not only facilitate the transport of photo-induced charges at interfaces, but also improve light absorption capacity due to coupling certain effects including localized surface plasmon resonance. The effect of band gap engineering on visible light absorption property will be studied, and the mechanism of photo-induced charge separation and transport will be revealed. High-performance heterostructured photoelectrodes will be fabricated, and several mechanisms for photoelectrochemical recognition and specific detection of biomacromolecules will be established. The study will not only enrich the family of low dimensional TMDs materials, but also gain an insight into photoelectric conversion, biomacromolecule recognition and specific detection. The results may have great potential in biomedical detection, diseases diagnosis, and curative effect forecast etc.

本项目针对单组份低维过渡金属二硫属化合物（TMDs）存在的可见光利用率不高、光生载流子易复合、光电转换效率低等问题，结合当前材料研究新热点以及生物医学领域对大分子检测、诊断与预测的迫切需求，拟采用元素掺杂与合金化等成分调控策略，合成出一系列低毒、高质量的低维多元TMDs可见光活性光电材料，基于能带工程提升可见光吸收利用率；基于功能导向的结构设计与先进的纳米加工技术，构筑异质结构复合光电体系，一方面通过耦合一些特殊的效应，进一步提高可见光吸收性能；另一方面利用材料功函数差异形成界面电场，增大光生载流子分离驱动力，抑或通过改善界面传输性能来抑制电子-空穴复合损失，全面提升载流子分离效率，揭示电荷分离、传输及复合机制，研制高性能异质结构光电极，建立生物大分子识别与检测机制。项目研究可加深对光电转换、生物识别与检测等基本科学问题的认识，相关成果将在生物检测、疾病诊断与疗效预测等领域具有应用价值。

低维过渡金属硫属化物（TMD）具有可调的能带结构和光电特性，其光学带隙适中，载流子迁移率高，生物相容性好，是一类极具竞争力的新型可见光活性材料。本项目针对单组分TMD可见光利用率不高、光生载流子易复合以及光电转换效率低等问题，主要开展了以下研究工作：（1）合成了系列多元TMD片层材料和TMD量子点，探讨了成分对能带结构及光电转换性能的调控规律；（2）构筑了多种高质量TMD/金属氧化物、TMD/硫化物、TMD/贵金属和TMD/碳等异质结构，研究了TMD作为光电活性材料、敏化剂或纳米酶的光电响应特性；（3）研究了各材料体系的光吸收性能，分析并确立了能带结构，探究了异质结构能带排列与光电转换效率的关系，剖析了影响激子分离效率、光生载流子传输与复合速率的主要因素，探讨了界面内建电场对光生载流子分离和传输的驱动作用，阐明了type II 型、p-n型及肖特基异质结构的光电转换机制；（4）基于空间位阻效应、敏化效应、表面等离子体共振效应、酶催沉淀反应、脂质体介导的放大以及DNAzyme引导的循环放大策略，建立了自供能、分离式及双模式输出等系列传感器，实现了对肿瘤坏死因子、β-淀粉样蛋白寡聚体、溶菌酶、胰岛素、腺苷和妥布霉素的超灵敏准确测定。上述研究成果丰富了低维TMDs材料体系，所构建的生物分析体系在临床诊断、生物医学检测与疗效预测等方面具有潜在的应用价值。在本项目的资助下，我们在高水平国际学术期刊上发表研究论文20篇，获批国家发明专利1项，培养已毕业博士研究生4名和硕士研究生1名。