An oligonucleotide or a nucleic acid covalently bonded to a perfluorocarbyl group has general formula ABE. A is a perfluorocarbyl group, including perfluorinated straight or branched aliphatic alkanes, perfluorinated straight or branched alkenes, perfluorinated straight or branched alkynes, and cyclic, optionally aromatic, perfluorocarbons, in which all of the H-atoms are substituted by F-atoms. B is a covalent bond, such as a covalent bond between the perfluorocarbyl group A and a C atom at the 2′； position of one or more sugars of the oligonucleotide or the nucleic acid, a covalent bond between the perfluorocarbyl group A and a C atom of a heterocyclic ring of one or more nucleobases of the oligonucleotide or the nucleic acid, or a covalent bond between the perfluorocarbyl group A and an O atom of one or more phosphate groups of the oligonucleotide or the nucleic acid. E is an oligonucleotide or a nucleic acid.
