纳米材料的荧光信号可以对生物细胞进行非接触式的高灵敏、低损伤探测，一直是研究的热点。然而，如何将有机、无机纳米材料结合制备成纳米复合荧光探针并用于细胞内信号测量，仍然是研究的难点。同时，临床研究发现聚肌苷酸胞苷酸(poly(i:c))不仅可作为免疫佐剂用于癌症临床治疗，而且可以直接诱导多种癌细胞的凋亡。但是，其在癌细胞内的作用位点以及相应的癌细胞抑制机理尚没有清晰的研究，因而限制其进一步临床应用。本项目利用纳米材料光学特性，选取碳化硅纳米颗粒对poly(i:c)进行示踪并对癌细胞内微环境pH值进行测量。同时选取金纳米颗粒对碳化硅荧光信号进行增强，将三者结合制备成有机、无机复合的纳米荧光探针。利用该复合荧光探针对poly(i:c)在癌细胞内作用位点及其引起癌细胞凋亡的机理进行研究，进而为癌症的早期诊断和靶向治疗提供实验依据。

Optical signals of nano-materials that can be detected without direct contact is sensitive, convenient, and noninvasive and impart important intracellular information. However, it is still a challenge to design the nano composite fluorescent probes based on organic and inorganic materials and make use of them for intracellular signals detection. Meanwhile, clinical studies have found that polyinosinic-polycytidylic acid (poly(i:c)) can not only be used as an immune adjuvant in clinical trials, but also triggering apoptosis of kinds of cancers. However, its sites of action in cells and the mechanisms of triggering apoptosis of cancers have not been well explored which limiting its further clinical applications. In this project, optical properties of nano materials have been used. Silicon carbide nano-particles are selected to fluorescent tracing the sites of action of poly(i:c) in cancers and detecting the pH changes in the microenvironment of cancers, based on the fluorescence characteristics of its surface state. Gold nano-particles are selected to enhance the fluorescence signals of silicon carbide based on the effect of surface plasma resonance. Nano composite structures combined these three materials will be made to explore the mechanisms of apoptosis and sites of action of poly(i:c) in cancers. And the results can provide assistants and evidences for early diagnosis and targeted therapy of cancers.