Resistive-Pulse Sensing Inside Single Living Cells
Resistive-Pulse Sensing Inside Single Living Cells
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DOI：
10.1021/jacs.9b13796
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发表时间：
2020-03-25
影响因子：
15
通讯作者：
Mirkin, Michael, V
中科院分区：
文献类型：
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作者：
Pan, Rongrong;Hu, Keke;Mirkin, Michael, V
电阻脉冲传感是一种广泛用于检测单个纳米级实体的技术，例如纳米颗粒和大分子，其可以阻止离子电流流过纳米孔或纳米移液管。虽然感兴趣的物种，例如，抗体、DNA和生物囊泡通常由活细胞产生，到目前为止，它们仅在本体溶液中被检测到，因为尚未报道生物系统中的局部连续脉冲感测。在这份报告中，我们使用了纳米移液管作为扫描离子电导显微镜（SICM）的尖端进行连续脉冲实验内固定的活细胞和它们的表面附近。当移液管刺穿细胞膜时发生的离子电流的特征变化用于监测其插入细胞质中。穿透后，在RAW 264.7巨噬细胞内检测到细胞囊泡（吞噬体、溶酶体和/或吞噬溶酶体）。使用小得多的移液管选择性地检测巨噬细胞细胞质中的10 nm Au纳米颗粒。转移性人乳腺细胞（MDAMB-231）释放的细胞外囊泡的原位连续脉冲检测也被证明。电化学连续脉冲实验通过将导电碳纳米移液管插入巨噬细胞中以对单个囊泡进行采样并测量其中所含的活性氧和氮物质（ROS/RNS）来进行。
Resistive-pulse sensing is a technique widely used to detect single nanoscopic entities such as nanoparticles and large molecules that can block the ion current flow through a nanopore or a nanopipette. Although the species of interest, e.g., antibodies, DNA, and biological vesicles, are typically produced by living cells, so far, they have only been detected in the bulk solution since no localized resistive-pulse sensing in biological systems has yet been reported. In this report, we used a nanopipette as a scanning ion conductance microscopy (SICM) tip to carry out resistive-pulse experiments both inside immobilized living cells and near their surfaces. The characteristic changes in the ion current that occur when the pipet punctures the cell membrane are used to monitor its insertion into the cell cytoplasm. Following the penetration, cellular vesicles (phagosomes, lysosomes, and/or phagolysosomes) were detected inside a RAW 264.7 macrophage. Much smaller pipettes were used to selectively detect 10 nm Au nanoparticles in the macrophage cytoplasm. The in situ resistive-pulse detection of extracellular vesicles released by metastatic human breast cells (MDAMB-231) is also demonstrated. Electrochemical resistive-pulse experiments were carried out by inserting a conductive carbon nanopipette into a macrophage cell to sample single vesicles and measure reactive oxygen and nitrogen species (ROS/RNS) contained inside them.