DNA tetrahedron for fluorescence anisotropy of intercalators

Abstract

BackgroundThe fluorescence anisotropy of intercalative dye plays important roles in nucleic acid analysis, the construction of fluorescent probes, and biosensing. However, there are few studies on the fluorescence anisotropy of intercalative dyes based on framework nucleic acids (FNA).PurposeThis study aims to use DNA tetrahedrons (TDN) as scaffold to build the fluorescence anisotropy probes of SYBR Green I, DAPI and DiYO-1.MethodsA series of TDN fluorescence anisotropy probes were constructed by precisely regulating the size of DNA tetrahedrons through DNA sequence design, characterizing DNA nanostructures by using synchrotron radiation small angle X-ray scattering (SAXS). The influence of TDN size on fluorescence anisotropy of SYBR Green I, DAPI and DiYO-1 was investigated by experiments.ResultsThe results show that the fluorescence anisotropy of probes increased with the increase of TDN size of SYBR Green I and DAPI, separately. For TDN/DiYO-1 probes, the fluorescence anisotropy decreases with the increase of TDN size as the edge length of TDN is between 7~20 bp, however, the fluorescence anisotropy increases as the edge length of TDN is bigger than 20 bp. After the dye interacted with the tetrahedron, the structure of DiYO-1 changes, resulting in the decrease of fluorescence anisotropy.ConclusionsTherefore, the fluorescence anisotropy of intercalators could be tuned by controlling the TDN size precisely. The fluorescence anisotropy probes based on FNA is expected to be an excellent probe.

Keywords

• fluorescence anisotropy
• dna tetrahedron (tdn)
• intercalators
• small angle x-ray scattering (saxs)