Department of Biomedical Engineering, The Hong Kong Polytechnic University , Hong Kong, P. R. China.
The Hong Kong Polytechnic University Shenzhen Research Institute , Shenzhen 518057, P. R. China.
ACS Appl Mater Interfaces. 2018 Jan 10;10(1):350-360. doi: 10.1021/acsami.7b18102. Epub 2017 Dec 22.
Here, we report the one-step in situ detection of targeted miRNAs expression in single living cancer cells via MoS nanosheet-based fluorescence on/off probes. The strategy is based on the folic acid (FA)-poly(ethylene glycol)-functionalized MoS nanosheets with adsorbed dye-labeled single-stranded DNA (ssDNA). Once the nanoprobes are internalized into cancer cells, the hybridization between the probes and target miRNA results in the detachment of dye-labeled ssDNA from MoS nanosheets surface, leading to the green fluorescence recovery. In this nanoprobe, MoS nanosheets offer advantages of high fluorescence quenching efficiency and extremely low toxicity. The FA conjugation could protect the probes and improve cancer cell transfection efficiency. The ability of this nanoprobe for endogenous miRNA detection in single living cancer cells is demonstrated for two types of cancer cells with different miRNA-21 expressions (MCF-7 and Hela cells). This functionalized MoS nanosheet-based nanoprobes could provide a sensitive and real-time detection of intracellular miRNA detection platform.
在这里，我们通过基于 MoS 纳米片的荧光开启/关闭探针，报道了一种在单个活癌细胞中一步原位检测靶向 miRNA 表达的方法。该策略基于叶酸（FA）-聚乙二醇-功能化的 MoS 纳米片，其表面吸附有染料标记的单链 DNA（ssDNA）。一旦纳米探针被内化进入癌细胞，探针与靶 miRNA 之间的杂交导致染料标记的 ssDNA 从 MoS 纳米片表面脱离，从而导致绿色荧光恢复。在这种纳米探针中，MoS 纳米片具有高荧光猝灭效率和极低毒性的优势。FA 缀合可以保护探针并提高癌细胞转染效率。该探针用于两种 miRNA-21 表达水平不同的癌细胞（MCF-7 和 Hela 细胞）中的内源性 miRNA 检测，证明了其在单个活癌细胞中检测内源性 miRNA 的能力。这种功能化的 MoS 纳米片基纳米探针可以提供一种灵敏且实时的细胞内 miRNA 检测平台。
