College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University , Jinan 250014, P.R. China.
Key Laboratory of Sensor Analysis of Tumor Marker Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology , Qingdao 266042, P.R. China.
Anal Chem. 2017 May 2;89(9):5124-5130. doi: 10.1021/acs.analchem.7b00697. Epub 2017 Apr 11.
The simultaneous imaging and quantification of multiple intracellular microRNAs (miRNAs) are particularly desirable for the early diagnosis of cancers. However, simultaneous direct imaging with absolute quantification of multiple intracellular RNAs remains a great challenge, particularly for miRNAs, which have significantly different expression levels in living cells. We designed dual-signal switchable (DSS) nanoprobes using the fluorescence-Raman signal switch. The intracellular uptake and dynamic behaviors of the probe are monitored by its fluorescence signal. Meanwhile, real-time quantitative detection of multiple miRNAs is made possible by measurements of the surface-enhanced Raman spectroscopy (SERS) ratios. Moreover, the signal 1:n ratio amplification mode only responds to low-abundance miRNA (asymmetric signal amplification mode) for simultaneous visualization and quantitative detection of significantly different levels of miRNAs in living cells. miR-21 and miR-203 were successfully detected in living MCF-7 cells, in agreement with in vitro results from the same batch of cell lysates. The reported dual-spectrum imaging method promises to offer a new strategy for the intracellular imaging and detection of various types of biomolecules.
同时对多个细胞内 microRNA（miRNA）进行成像和定量分析，对于癌症的早期诊断尤为理想。然而，对于具有显著不同表达水平的 miRNA 等物质，同时直接对多个细胞内 RNA 进行绝对定量成像仍然是一个巨大的挑战。我们设计了使用荧光 - 拉曼信号开关的双信号可切换（DSS）纳米探针。通过其荧光信号来监测探针的细胞内摄取和动态行为。同时，通过表面增强拉曼光谱（SERS）比值的测量，可以实现对多个 miRNA 的实时定量检测。此外，信号 1:n 比放大模式仅对低丰度 miRNA 有响应（不对称信号放大模式），从而可以在活细胞中对 miRNA 的显著不同水平进行同时可视化和定量检测。成功地在活 MCF-7 细胞中检测到了 miR-21 和 miR-203，与同一批细胞裂解物的体外结果一致。所报道的双谱成像方法有望为各种类型生物分子的细胞内成像和检测提供新策略。
