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 of Ag^+ 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 of cysteine in the 0.2–3.0 μM range. The method can successfully manipulate the assembly and disassembly of DNA in HCR.
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 ofDNA-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 of cysteine in the 0.2-3.0 μM range. The method can successfully manipulate the assembly and disassembly of DNA in HCR.
基金
supported by the National Natural Science Foundation of China (21375153)
the Fundamental Research Funds for the Central Universities (171gpy79)
