Efficient Separation of Nucleic Acids with Different Secondary Structures by Metal–Organic Frameworks

We report the use metal organic frameworks for the selective inclusion of nucleic acids with different size, shape and capability of conformational transition. Three MOFs, Co-IRMOF-74-II, -III, and -IV, composed of Co2+ and organic linkers (linker-II, -III and -IV), respectively, were used for nucleic acid inclusion into their pores from solution, which is a spontaneous process from disordered free state to restricted ordered state. The pores of these MOFs were precisely controlled to provide selectivity between different structural nucleic acids. These MOFs preferentially adsorb flexible single strand nucleic acids due to spatial size matching selection and preferentially adsorb unstable rigid structural nucleic acids with larger cross-section size owing to conformations changes. In addition, the transcribed RNA enters the MOF pores in a directional manner, giving priority to the 3' end entering the MOF pores. Furthermore, under complicated mixtures of various structures, flexible single strand nucleic a...