基于SERS的卫星型贵金属/无机非金属复合纳米探针的制备和表征

Novel satellite-like SERS nano-probes of noble metal/inorganic non-metal composites, equipped with abundant “hot spots” in one single nanoparticle, are proposed and synthesized to meet the requirement of multimodal characteristics involved in cancer cell specific targeting and therapy, namely, excellent chemical stability, highly amplified SERS (surface-enhanced Raman scattering) signal intensity, and LSPR (localized surface plasmon resonance) near-infrared-absorbing. Either galvanic replacement reaction or step-by-step nucleation-growth technology is adopted to result in multi-hierarchical structures. The roles of temperature, the size and morphology of the primary structure and inorganic non-metal interlayer, the constituent and concentration of metal sacrifice template, etc. in controlling the morphological evolution are extensively investigated. Raman techniques and three dimensional finite-difference time-domain method are utilized to analyze the interior relationship between hierarchical structures and their optical properties. The spatial structure and its synthetic strategy are further optimized to achieve a synergistic effect between SERS signal intensity and LSPR near-infrared-absorbing. The as-synthesized nanoparticles could be readily modified with antibodies to explore their potentials in specific diagnosis and photothermal therapy of cancer cells.

本项目拟针对表面增强拉曼光谱（SERS）在肿瘤细胞靶向识别与治疗中的应用要求，以提高纳米结构稳定性、增大SERS强度和实现局域等离子体共振（LSPR）吸收近红外区间可调为研究目标，采用流电置换反应和多次成核-生长技术，设计并制备可衍生多重“热点”的卫星型贵金属/无机非金属复合纳米探针。通过研究初级结构的形貌尺寸、无机非金属隔层成分与尺寸、金属牺牲模板的种类和反应温度等对微结构的影响规律，深入探索微观结构的生长机制。利用光谱表征手段与三维时域有限差分理论模拟方法，分析贵金属/无机非金属复合纳米探针的多级微结构与其光学性质的内在联系，进一步优化纳米探针的空间结构，实现SERS强度高与LSPR近红外吸收的协同效应。将该卫星型功能化纳米探针材料应用于生物医用领域，实现生物体内肿瘤细胞靶向识别与光热治疗的目标。

课题针对表面增强拉曼光谱（SERS）在生物和食品检测中的应用要求，以提高纳米结构稳定性、增大SERS灵敏度、实现局域等离子体共振（LSPR）吸收近红外区间可调、制备柔性薄膜检测基底和仿生表面超疏水改性为研究目标，采用偶联自组装、微波合成、电化学沉积和界面合成组装等技术，设计并制备可衍生多重“热点”的卫星型贵金属/贵金属、贵金属/无机非金属和贵金属/有机高聚物复合SERS基底。通过研究初级结构的形貌尺寸、无机非金属成分与结构、有机高聚物组成和性质、贵金属纳米材料种类和形状、制备条件和检测环境等因素对微结构的影响规律，深入探索微观结构的生长和组装机制。利用光谱等表征手段、密度泛函理论和三维时域有限差分理论模拟方法，分析复合SERS基底的多级微结构与其光学性质的内在联系，进一步优化微纳米材料的空间结构，实现SERS灵敏度与LSPR调控、基底柔性和表面浸润性等功能的协同效应，将功能化复合纳米材料应用于生物医用和食品检测等领域。