State Key Laboratory of Bioelectronics, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , People's Republic of China.
State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210093 , People's Republic of China.
Anal Chem. 2018 Dec 4;90(23):14056-14062. doi: 10.1021/acs.analchem.8b04179. Epub 2018 Nov 15.
In this work, a simple and ultrasensitive localized surface plasmon resonance (LSPR) method that use Au nanoflowers (AuNFs) as a probe was designed for in situ monitoring of alkaline phosphatase (ALP) activity. The AuNFs were fabricated by hydrogen tetrechloroaurate-induced oxidative disruption of polydopamine-coated Au nanoparticles (AuNPs), and subsequently, growth of Au nanopetals on AuNPs occurred. The as-prepared AuNFs showed a much higher LSPR capability and stronger scattering color change than AuNPs. The strategy for in situ cellular ALP activity detection relied on the deposition of Ag on the AuNFs surface, which changed the morphology of AuNFs and led to a tremendous LSPR response and scattering color change. The deposition of Ag shell on AuNFs was related to ALP activity, where ALP catalyzed the hydrolysis of l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate to form l-ascorbic acid (AA), and then AA reduced Ag to Ag and deposited onto AuNFs. With this concept, the ALP activity could be monitored with a detection limit of 0.03 μU L. Meanwhile, the ALP activity of single HepG2 cells and HEK 293 cells was tracked with a proposed approach, which indicated the trace expression level of ALP in HEK 293T cell and overexpressed level of ALP in HepG2 cells. After treatment with drugs, the cellular ALP activity of HepG2 cells was decreased with the treating time and dose increasing. Therefore, the proposed strategy could be used for tracking the cellular ALP activity, which paved a new avenue for cell studies and held great potential for discovering novel ALP-based drugs applications.
在这项工作中，设计了一种简单且超灵敏的局域表面等离子体共振（LSPR）方法，该方法使用金纳米花（AuNFs）作为探针，用于原位监测碱性磷酸酶（ALP）活性。AuNFs 通过四氯金酸诱导的聚多巴胺包覆的金纳米粒子（AuNPs）的氧化破坏来制备，随后，Au 纳米花瓣在 AuNPs 上生长。与 AuNPs 相比，所制备的 AuNFs 表现出更高的 LSPR 能力和更强的散射颜色变化。用于原位细胞 ALP 活性检测的策略依赖于 Ag 在 AuNFs 表面的沉积，这改变了 AuNFs 的形态，并导致巨大的 LSPR 响应和散射颜色变化。Ag 壳在 AuNFs 上的沉积与 ALP 活性有关，其中 ALP 催化 l-抗坏血酸 2-磷酸半镁盐水合物的水解形成 l-抗坏血酸（AA），然后 AA 将 Ag 还原为 Ag 并沉积在 AuNFs 上。基于此概念，可以检测到 0.03 μU L 的 ALP 活性。同时，使用所提出的方法跟踪了单个 HepG2 细胞和 HEK 293 细胞的 ALP 活性，表明了 HEK 293T 细胞中 ALP 的痕量表达水平和 HepG2 细胞中 ALP 的过表达水平。用药物处理后，随着处理时间和剂量的增加，HepG2 细胞的细胞内 ALP 活性降低。因此，所提出的策略可用于跟踪细胞内 ALP 活性，为细胞研究开辟了新途径，并为发现新型基于 ALP 的药物应用提供了巨大潜力。
