本论文以聚丙烯酸钠(PAAS)作钝化剂用微波辅助热解葡萄糖(Glu)的方法合成了具有强绿色荧光的碳点(CDs)，叶酸分子(FA)可以通过氢键吸附在碳点表面并使其荧光猝灭，基于此设计了叶酸-碳点(FA-CDs)复合荧光探针。在复合探针溶液中加入叶酸受体，由于叶酸和叶酸受体(FR)之间有很强的特异性结合作用，叶酸分子从碳点表面释放与叶酸受体结合，碳点荧光恢复，该复合探针荧光背景低，对叶酸受体的检测灵敏度高。大多数肿瘤细胞表面叶酸受体过度表达，因此，复合探针FA-CDs能够作为特异性检测肿瘤细胞的新工具。利用HeLa和HepG2两种肿瘤细胞及HEK-293正常细胞，对复合探针FA-CDs用于特异性检测肿瘤细胞的可行性进行了研究。MTT实验结果表明，合成的碳点具有较低生物毒性；荧光显微成像实验结果显示，复合探针可通过靶向turn-on荧光成像对肿瘤细胞进行特异性识别和检测；本文还对碳点及复合探针FA-CDs在细胞成像中的光稳定性进行了研究，实验结果表明碳点光稳定性好，即使连续照射2 h依然能获得高分辨率的细胞成像图，二者均可用于较长时间荧光成像。以上结果表明复合探针FA-CDs同时具备靶向性和长时间荧光成像的特点，这不仅为准确检测肿瘤细胞提供了新工具也为荧光辅助外科手术及获取肿瘤细胞的实时信息创造了可能。此外，本文还研究了金纳米三角片的合成，并采用高分辨透射电镜和紫外吸收光谱对其表征，实验结果表明合成的金纳米三角片形态均一且产率较高，接着又探索了在金纳米三角片表面包覆二氧化硅的方法，高分辨透射电镜显示二氧化硅壳层包覆均匀，金纳米三角片的各向异性强，其表面易产生较强电磁场，符合等离子体基元共振效应产生的条件，为下一步实现荧光增强奠定了基础。

Developing efficient methods for visual detection of cancer cells has the potential to contribute greatly to basic biological research and early diagnosis of cancer. Here, we report facile and one-step synthesis of green fluoresence carbon dots (CDs) with the help of a new passivating agent – poly(acrylate sodium) (PAAS). Based on the as-prepared CDs, a novel turn-on fluorescence probe was designed for targeting imaging of cancer cells via hydrogen-bond interaction between the folic acid and CDs (FA-CDs). Intracellular experiments indicated that FA-CDs probe could accurately distinguish folate receptor (FR)-positive cancer cells in different cell mixture with turn-on mode. In particular, combining the targeting of FA-CDs probe with the excellent photostability of CDs has inestimable meaning for fluorescence-assisted surgical resection and acquisition real-time information about tumor cells. Obviously, the as-prepared FA-CDs probe may have great potential as a high-performance platform for accurately recognizing special cancer cells, which may provide new tools for cancer prognosis and therapy.Additionally, we study the synthese of gold triangular nanoplates (AuNPs). The experiments of high resolution transmission electron microscopy (TEM) and UV-vis absorption are carried out to characterize the morphotogy of the AuNPs, which indicate that the AuNPs have a uniform dispersion. Then, we coat SiO2 on the surface of AuNPs and the result of TEM show that the thickness of SiO2 shell is well-distributed. High anisotropy of AuNPs make it easy to generate strong electric field, which lay the foundation for realizing fluorescence enhancement.