Abnormal cellular biothiol levels are related to many abnormal physiological processes, including cancer, multidrug resistance and Alzheimer's disease, etc. In this study, the nano-aggregates of the background-free surface-enhanced Raman scattering (SERS) tags were constructed and developed for the intracellular biothiol detection via a target-triggered disaggregation process. The plasmonic nano-tags were prepared by coating gold nanoparticles with a Raman reporter (4-mercaptobenzonitrile, MBN), which exhibits a single strong peak in the cellular Raman silent region (1800-2800 cm-1) that can eliminate the background interference of cells. Interestingly, this reporter is also the host ligand for guest mercury ions. The coordination of mercury/cyano group induce the formation of the pre-aggregates of nano-tags and the formed nano-aggregates allowing strong SERS signals of reporters. Intracellular biothiols show higher affinity to mercury ions than the SERS tags do, which can break the hot spot geometry and redisperse tags by taking away mercury ions from nano-aggregates, which dramatically decreases the SERS signals of reporters previously laid on gold nanoparticles. The developed SERS "turn off" method was used for biothiol detections in normal, cancer, drug-resistant cells, and biothiol dynamics during chemotherapy. The results demonstrate that the drug-resistant cells (MCF-ADR) lie in a higher biothiol level than cancer cells (MCF-7 and HepG2), and the normal cells (LO2) give a lower biothiol concentration compared with cancer cells. Moreover, most cancer cells are more sensitive to doxorubicin compared with the normal ones. This study provides an important strategy in learning the cellular processes that are highly associated with intracellular biothiol level.

中文翻译：

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目标触发的热点分散体，可通过无背景的表面增强拉曼散射标签检测细胞中的生物硫醇。

细胞生物硫醇水平异常与许多异常生理过程有关，包括癌症，多药耐药性和阿尔茨海默氏病等。在这项研究中，构建并开发了无背景表面增强拉曼散射（SERS）标签的纳米聚集体，用于通过目标触发的分解过程进行细胞内生物硫醇检测。通过用拉曼报道分子（4-巯基苄腈，MBN）包被金纳米颗粒来制备等离子纳米标签，该报道分子在细胞拉曼无声区（1800-2800 cm-1）中表现出单个强峰，该峰可以消除干扰的背景干扰。细胞。有趣的是，该报告者还是客体汞离子的主体配体。汞/氰基的配位诱导了纳米标签的预聚集体的形成，并且所形成的纳米聚集体允许报道基因的强SERS信号。细胞内生物硫醇对汞离子的亲和力比SERS标签更高，后者可以通过从纳米聚集体中去除汞离子来打破热点几何形状并重新分散标签，从而大大降低了以前放置在金纳米颗粒上的报告分子的SERS信号。已开发的SERS“关闭”方法用于正常，癌症，耐药性细胞中的生物硫醇检测，以及化学疗法中的生物硫醇动力学。结果表明，耐药细胞（MCF-ADR）的生物硫醇水平高于癌细胞（MCF-7和HepG2），而正常细胞（LO2）的生物硫醇浓度低于癌细胞。而且，与正常细胞相比，大多数癌细胞对阿霉素更敏感。这项研究为学习与细胞内生物硫醇水平高度相关的细胞过程提供了重要的策略。