二元贵金属多级微纳结构的可控制备、组装及其高灵敏SERS器件的构筑

This project would focus on controlled synthesis of hierarchical micro-/nano-structures of noble bimetals by sol-gel, electrochemistry, and hydro(solvo)thermal methods, via tuning the crystal plane growth with the assistance of structure directing agents. These nanostructures can be further modified and functionalized by different chemical and physical methods, and their SERS activities would be examined with decolorizing peroxidase and laccase as Raman probes to select the ones with high-quality and distinctive enhancement. Meanwhile, much work would be conducted for design and fabircation of uniform Raman substrates at glassy carbon, silver, platinum, and quartz supports, using assembly, electrodeposition, casting, or gravity settling technique, followed by investigating the characteristic structures, bioactivity, enhancement factor, stability, reproductibility, interfacial orientation, and sensitivity of the immobilized probes. Furthermore, the heterogenious electron transfer mechanism and interfacial catalysis reaction of the probes would be explored by SERS technique coupled with electrochemistry. Besides, many efforts would be made for the development of a SERS model of the as-prepared nanostructures to have a deep insight on the relationship between the microstructural parameters and the corresponding Raman activity, illustrating their enhanced Raman mechanism. As a result, multi-functional Raman devices with high sensitivity, reproducibility and stability would be designed and constructed for fast, sensitive, reproductive, real-time, and in-situ detection of the probes in bioanalysis, environmental and food analysis.

本项目拟采用溶胶凝胶法、电化学法、水热/溶剂热法等材料合成技术，通过调控分子来控制晶面生长，可控制备二元贵金属多级微纳结构。通过物理或化学修饰技术对其进行改性或功能嫁接。以脱色过氧化酶或漆酶为探针分子来考察材料的拉曼活性，筛选高拉曼活性的二元贵金属多级微纳结构及其合成体系。利用组装、电沉积、滴涂或沉降法等在玻碳、银、金或石英基底表面构筑均一的拉曼活性基底。研究探针分子在拉曼基底上的特征结构、生物活性、增强因子、稳定性、重现性、界面取向、灵敏度等。结合电化学联用技术来研究探针分子的异相电子传递机制和表面催化反应等。探讨材料微观结构与拉曼活性之间的构效关系，建立二元贵金属拉曼器件的 SERS 理论模型，揭示拉曼信号的增强机制。通过该项目发展基于二元贵金属多级微纳结构的高灵敏、高稳定、高重现的拉曼器件，实现底物分子的快速、灵敏、实时和原位检测，并拓展其在环境分析、生化分析和食品分析等领域的应用。

本项目开发了尿素、胸腺嘧啶、胞嘧啶、黄嘌呤、叶酸、尿囊素、甲氨喋呤、L-谷氨酸、L-精氨酸、L-脯氨酸、三羟甲基氨基甲烷、二甲双胍、4-氨基吡啶、二羟丙茶碱、三聚氰胺、咖啡因、3-氨基吡咯烷、乙二胺、N-甲基咪唑、2,4-二羟基吡啶、离子液体、聚胞苷酸、聚L-赖氨酸等30多个调控分子，可控构筑了一系列多级微纳双金属材料，详细研究了金属前驱体还原、聚集、成核、晶化、生长等过程，深入探讨了双金纳米晶的生长机制，解释了产物形貌、尺度、组分、暴露晶面等微观结构参数与关键实验条件之间的内在关系。.这些双金属多级微纳材料如 AgPt@Ag核壳纳米晶、AuPd多枝状合金、枝状AgPt合金纳米花、Au-Pt纳米刺、AgPt纳米珊瑚、神经元结构的Au-Pd纳米合金等都表现出优异的拉曼增强效应，以这些材料作为新的拉曼增强基底材料，可以用于高灵敏测定4-巯基吡啶、4-硝基噻吩、4-巯基苯甲酸、4-巯基苯硼酸、4-硝基苯硫酚、葡萄糖等，并深入探讨SERS效应增强机制。同时，利用中空枝状AuPtAg纳米晶、还原氧化石墨烯负载的AgPt纳米环、Au@Pt纳米晶、多枝状AuPd@Au纳米晶、AuAg 空心纳米晶、单分散AuPt纳米绒球、多级状AuPd纳米链网、PtCu空心纳米框等材料构建了多功能、多元协同纳米界面，发展多功能光电免疫传感器件，并用于高选择、高灵敏地测定多种肿瘤标记物（PSA、CA199 、CA 19-9 、CA 15-3、CEA等）。.在该基金资助下，项目负责人以第一作者或通讯作者发表SCI期刊论文80余篇，其中SCI一区论文42篇，影响因子大于7.0的10篇（4篇Biosens. Bioelectron.；5篇J. Mater. Chem. A；1篇Nanoscale），论文被引用1000余次，其中5篇论文为ESI高被引论文，2篇论文引用超过100次（J. Mater. Chem. C, 2015, 3, 73–78；J. Mater. Chem. A, 2015, 3, 290–296）；项目执行期间获授权国家发明专利3件，在审核国家发明专利3件；目前仍有部分实验数据正在整理和论文撰写中。四年来共培养10余名研究生，其中6名同学获国家奖学金、3名同学获省优秀毕业生。经过四年的努力，已初步建立了一支严谨、求实、创新的科研团队，本研究工作达到了预期目标。