State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130012, China.
Nanoscale. 2018 Jan 25;10(4):1622-1630. doi: 10.1039/c7nr08636a.
The pH value of subcellular organelles in living cells is a significant parameter in the physiological activities of cells. Its abnormal fluctuations are commonly believed to be associated with cancers and other diseases. Herein, a series of surface-enhanced Raman scattering (SERS) nanosensors with high sensitivity and targeting function was prepared for the quantification and monitoring of pH values in mitochondria, nucleus, and lysosome. The nanosensors were composed of gold nanorods (AuNRs) functionalized with a pH-responsive molecule (4-mercaptopyridine, MPy) and peptides that could specifically deliver the AuNRs to the targeting subcellular organelles. The localization of our prepared nanoprobes in specific organelles was confirmed by super-high resolution fluorescence imaging and bio-transmission electron microscopy (TEM) methods. By the targeting ability, the pH values of the specific organelles can be determined by monitoring the vibrational spectral changes of MPy with different pH values. Compared to the cases of reported lysosome and cytoplasm SERS pH sensors, more accurate pH values of mitochondria and nucleus, which could be two additional intracellular tracers for subcellular microenvironments, were disclosed by this SERS approach, further improving the accuracy of discrimination of related diseases. Our sensitive SERS strategy can also be employed to explore crucial physiological and biological processes that are related to subcellular pH fluctuations.
活细胞内细胞器的 pH 值是细胞生理活动的一个重要参数。人们普遍认为，其异常波动与癌症和其他疾病有关。在此，我们制备了一系列具有高灵敏度和靶向功能的表面增强拉曼散射（SERS）纳米传感器，用于定量和监测线粒体、细胞核和溶酶体中的 pH 值。这些纳米传感器由金纳米棒（AuNRs）组成，金纳米棒表面修饰有 pH 响应分子（4-巯基吡啶，MPy）和可以将 AuNRs 靶向递送至特定细胞器的肽。通过超分辨荧光成像和生物透射电子显微镜（TEM）方法证实了我们所制备的纳米探针在特定细胞器中的定位。通过靶向能力，可以通过监测具有不同 pH 值的 MPy 的振动光谱变化来确定特定细胞器的 pH 值。与已报道的溶酶体和细胞质 SERS pH 传感器相比，这种 SERS 方法揭示了线粒体和细胞核更准确的 pH 值，它们可以作为两个额外的细胞内细胞器微环境示踪剂，进一步提高了相关疾病的鉴别准确性。我们灵敏的 SERS 策略还可以用于探索与细胞内 pH 波动相关的关键生理和生物学过程。
