PDF(Pubmed)
Abstract：
A fluorogenic aptamer (FA)-based hybridization chain reaction (HCR) could provide a sensitive and label-free signal amplification method for imaging molecules in living cells. However, existing FA-HCR methods usually face some problems, such as a complicated design and significant background leakage, which greatly limit their application. Herein, we developed an FA-centered HCR (FAC-HCR) method based on a remote toehold-mediated strand displacement reaction. Compared to traditional HCRs mediated by four hairpin probes (HPs) and two HPs, the FAC-HCR displayed significantly decreased background leakage and improved sensitivity. Furthermore, the FAC-HCR was used to test a non-nucleic acid target, apurinic/apyrimidinic endonuclease 1 (APE1), an important BER-involved endonuclease. The fluorescence analysis results confirmed that FAC-HCR can reach a detection limit of 0.1174 U/mL. By using the two HPs for FAC-HCR with polyetherimide-based nanoparticles, the activity of APE1 in living cells can be imaged. In summary, this study could provide a new idea to design an FA-based HCR and improve the performance of HCRs in live cell imaging.
摘要：
基于荧光适体（FA）的杂交链反应（HCR）可以提供一种灵敏且无标记的信号放大方法，用于对活细胞中的分子进行成像。然而,现有的FA-HCR方法通常面临一些问题，例如复杂的设计和重大的背景泄漏，这极大地限制了它们的应用。在这里，我们开发了一种以FA为中心的HCR(FAC-HCR)方法,该方法基于远程立足点介导的链置换反应.与由四个发夹探针（HP）和两个HP介导的传统HCR相比，FAC-HCR显示背景渗漏显著减少,灵敏度提高.此外，FAC-HCR用于测试非核酸靶标，无嘌呤/无嘧啶核酸内切酶1（APE1），一种重要的BER相关核酸内切酶。荧光剖析成果证实FAC-HCR的检测限能到达0.1174U/mL。通过使用基于聚醚酰亚胺的纳米颗粒的FAC-HCR的两个HP，APE1在活细胞中的活性可以成像。总之,本研究为设计基于FA的HCR和提高HCR在活细胞成像中的性能提供了新的思路.
