不同类型的肿瘤相关生物分子分布于细胞的不同部位，有些分布在细胞膜上，有些分布在细胞质内。然而，大部分已有的检测方法主要集中于检测单一种类的肿瘤相关分子，无法得到从细胞表面到细胞质内多层次的相关信息。因此，本项目提出一种可层层解析细胞表面肿瘤相关聚糖以及细胞质内肿瘤相关生物分子的复合等离子体纳米探针。以金纳米粒子为基底，在其表面功能化可特异性识别细胞膜糖基的荧光分子，同时将荧光标记的可靶向识别细胞内肿瘤相关的分子信标修饰在纳米粒子表面。探针通过与细胞表面糖基末端的相互作用进入细胞，其表面的糖基识别荧光分子解离并与细胞膜糖基末端结合，标记在细胞表面。探针进入细胞后，其表面修饰的分子信标可特异性结合细胞质内目标分子，脱离金纳米粒子表面，产生荧光信号。同时在暗场显微镜下，通过观察金纳米颗粒颜色及散射光谱的变化，可定位监测探针进入细胞后的分布情况以及探针表面分子信标反应过程。

Different types of tumor-related biomolecules are distributed at various parts of cells. Some of them locate on the membrane, and some of them exist in the cytoplasm. However, most of the reported detection methods focus on the analysis of a certain type of tumor-related molecules, thus fail to obtain the multilayer information from cell surface to cytoplasm. Therefore, this project proposes a composite plasmonic nanoprobe for the layer-by-layer analysis of tumor-related biomolecules from cell surface glycans to intracellular tumor markers. Gold nanoparticles (AuNPs) are used as the substrates, and a glycan-specific fluorescent molecule and a molecular beacon (MB) for specific recognition of intracellular target molecules are functionalized on the AuNP surface. The obtained nanoprobes enter cells through the interactions with cell surface glycans with the glycan-specific fluorescent molecules leaving from the probe surface and binding with the target glycans on cell membrane. After the probes enter into the cytoplasm, the MB can specifically recognize the target tumor-related molecule in cytoplasm and depart from the probe surface to produce fluorescent signals. At the same time, the changes in color and scattering spectra of AuNPs can be observed under a dark-field microscope, which are used for the localization of the intracellular probes and the monitoring of MB departure processes on probe surface.