An Ag+-stabilized triplex DNA molecular switch controlled hybridization chain reaction

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2017,（12）
• 页码范围: 1575-1580
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s11426-017-9124-0

摘要

We described a new strategy to combine hybridization chain reaction (HCR) process and triplex DNA through Ag+/cysteine,thus to pursue the controllable process of HCR.H1,a specially-designed triplex DNA,with homopyrimidines which can bind to dsDNA through Hoogsteen bonding,forming a cap-like triplex DNA.The presence ofAg+ can play the role as a H1 locker to stop initiator from triggering HCR process,forming Ag+-stabilized triplex DNA molecular switch (denoted as Ag+-STDMS).However,the strong binding ability of cysteine towards Ag+ forming stable Ag+-cysteine can release the locking tail of H1 and realize the retriggering of HCR.This study presented a promising tool to regulate the self-assembly processes of DNA-based nanostructures in neutral environment.Under the optimum conditions,fluorescence intensity (peaking at 582 nm) of HCR is proportional to the concentration of Ag+ in the 0.2-4.0 μM range.Within the presence of Ag+,the fluorescence intensity is also proportional to the concentration ofcysteine in the 0.2-3.0 μM range.The method can successfully manipulate the assembly and disassembly of DNA in HCR.