Functional nucleic acid-based cell imaging and manipulation

Cells are the basic structural and functional units of organisms.Dynamic analysis and manipulation of specific components in living cells would provide valuable information for the study of related biological processes.Advances in fluorescence microscopy have allowed real-time monitoring of biological events at the molecular level.Meanwhile,the development of highperformance fluorescence probes has become a critical issue.Functional nucleic acids(FNAs)are oligonucleotides with special chemical and biological functions,and aptamers with excellent molecular recognition capability are one of the most important representatives.They have attracted extensive attention in the field of live-cell study,owing to intrinsic advantages of simple synthesis,convenient modification,low immunogenicity and high programmability.This review focuses on recent research progress in fluorescence imaging and manipulation of cells using FNAs,particularly aptamers,as the molecular tools.Finally,a summary is provided and the related challenges are discussed.

Functional Xeno Nucleic Acids for Biomedical Application

Functional nucleic acids(FNAs)refer to a type of oligonucleotides with functions over the traditional genetic roles of nucleic acids,which have been widely applied in screening,sensing and imaging fields.However,the potential application of FNAs in biomedical field is still restricted by the unsatisfactory stability,biocompatibility,biodistribution and immunity of natural nucleic acids(DNA/RNA).Xeno nucleic acids(XNAs)are a kind of nucleic acid analogues with chemically modified sugar groups that possess improved biological properties,including improved biological stability,increased binding affinity,reduced immune responses,and enhanced cell penetration or tissue specificity.In the last two decades,scientists have made great progress in the research of functional xeno nucleic acids,which makes it an emerging attractive biomedical application material.In this review,we summarized the design of functional xeno nucleic acids and their applications in the biomedical field.

A highly sensitive DNA-AIEgen-based ＂turn-on＂ fluorescence chemosensor for amplification analysis of Hg^2+ ions in real samples and living cells

Functional nucleic acids(FNAs)-based biosensors have shown great potential in heavy metal ions detection due to their low-cost and easy to operate merits. However, in most FNAs based fluorescence probes, the ingenious designs of double-labeled(fluorophore and quencher group) DNA sequence, not only bring the annoyance of organic synthesis, but also restrict its use as a robust biosensor in practical duties. In this paper, we design a simple AIEgens functional nucleic acids(AFNAs) probe which consists of only fluorogen but no quencher group. With the help of duplex-specific nuclease(DSN) enzyme based target recycling, high fluorescence signal and superior sensitivity towards Hg^(2+) are achieved. This robust assay allows for sensitive and selective detection of Hg^(2+) in real water samples and mapping of intracellular Hg^(2+), without double-labeling of oligonucleotide with a dye-quencher pair, nor the multiple assay steps.