Advanced Photonics Center, Southeast University, Nanjing 210096, Jiangsu, China.
Talanta. 2012 Aug 15;97:368-75. doi: 10.1016/j.talanta.2012.04.047. Epub 2012 Apr 30.
We report a dual mode cancer cell targeting probe based on CdTe quantum dots (QDs) conjugated, silica coated Au@Ag core-shell nanorods (Au@Ag NRs), which can generate both surface enhanced Raman scattering (SERS) and fluorescence signals. In such a probe, folic acid (FA) is used as a targeting ligand for folate receptors (FRs) overexpressed cancer cells. To synthesize the probe, Au@Ag NRs were first prepared to serve as the SERS substrates by coating an Ag shell on the gold nanorods. Then the Au@Ag NRs were labeled with 4-mercaptobenzoic acid (4MBA) to generate SERS signals, followed by being coated with a silica shell through a modified Stöber method. Finally, CdTe QDs and FA were conjugated to the silica coated Au@Ag NRs by the carbodiimide chemistry to yield fluorescence and the targeting ability, respectively. To validate the targeting capability of the probe, in vitro experiments were conducted, using HeLa cells with overexpressed FRs as the model target cells and MRC-5 cells with a low folate receptor expression level as the negative control. Both the fluorescence imaging and the SERS mapping results confirmed that the proposed probe can be used as an efficient cancer cell targeting agent. This kind of multifunctional probe has great potential in the diagnosis and therapeutics of cancerous diseases due to its specific targeting and multiplex imaging abilities, especially in the simultaneous tracking of multiple components in a hybrid bio-system.
我们报告了一种基于 CdTe 量子点 (QDs) 偶联、硅涂层 Au@Ag 核壳纳米棒 (Au@Ag NRs) 的双模癌细胞靶向探针,它可以产生表面增强拉曼散射 (SERS) 和荧光信号。在这种探针中,叶酸 (FA) 被用作叶酸受体 (FRs) 过度表达癌细胞的靶向配体。为了合成探针,首先制备 Au@Ag NRs 作为 SERS 底物,在金纳米棒上涂覆 Ag 壳。然后,Au@Ag NRs 用 4-巯基苯甲酸 (4MBA) 标记以产生 SERS 信号,然后通过改进的 Stöber 方法用硅壳包覆。最后,通过碳二亚胺化学将 CdTe QDs 和 FA 偶联到硅涂层的 Au@Ag NRs 上,分别赋予荧光和靶向能力。为了验证探针的靶向能力,进行了体外实验,使用 FRs 过度表达的 HeLa 细胞作为模型靶细胞,FRs 低表达的 MRC-5 细胞作为阴性对照。荧光成像和 SERS 图谱结果均证实,该探针可用作高效的癌细胞靶向剂。由于其特定的靶向和多重成像能力,这种多功能探针在癌症疾病的诊断和治疗中具有很大的潜力,特别是在混合生物系统中同时跟踪多个成分。