RESUMO
Spatial and temporal distributions of metal ions in vitro and in vivo are crucial in our understanding of the roles of metal ions in biological systems, and yet there is a very limited number of methods to probe metal ions with high space and time resolution, especially in vivo. To overcome this limitation, we report a Zn2+-specific near-infrared (NIR) DNAzyme nanoprobe for real-time metal ion tracking with spatiotemporal control in early embryos and larvae of zebrafish. By conjugating photocaged DNAzymes onto lanthanide-doped upconversion nanoparticles (UCNPs), we have achieved upconversion of a deep tissue penetrating NIR 980 nm light into 365 nm emission. The UV photon then efficiently photodecages a substrate strand containing a nitrobenzyl group at the 2'-OH of adenosine ribonucleotide, allowing enzymatic cleavage by a complementary DNA strand containing a Zn2+-selective DNAzyme. The product containing a visible FAM fluorophore that is initially quenched by BHQ1 and Dabcyl quenchers is released after cleavage, resulting in higher fluorescent signals. The DNAzyme-UCNP probe enables Zn2+ sensing by exciting in the NIR biological imaging window in both living cells and zebrafish embryos and detecting in the visible region. In this study, we introduce a platform that can be used to understand the Zn2+ distribution with spatiotemporal control, thereby giving insights into the dynamical Zn2+ ion distribution in intracellular and in vivo models.
Assuntos
DNA Catalítico/química , Corantes Fluorescentes/química , Nanopartículas/química , Zinco/análise , Alcanossulfonatos/química , Alcanossulfonatos/toxicidade , Animais , Compostos Azo/química , Compostos Azo/toxicidade , Sequência de Bases , DNA Catalítico/síntese química , DNA Catalítico/toxicidade , Fluoresceínas/química , Fluoresceínas/toxicidade , Fluorescência , Corantes Fluorescentes/toxicidade , Fluoretos/química , Fluoretos/toxicidade , Células HeLa , Humanos , Raios Infravermelhos , Microscopia Confocal , Microscopia de Fluorescência , Nanopartículas/efeitos da radiação , Nanopartículas/toxicidade , Túlio/química , Túlio/toxicidade , Itérbio/química , Itérbio/toxicidade , Ítrio/química , Ítrio/toxicidade , Peixe-ZebraRESUMO
A dearomative reduction of simple arenes has been developed which employs a visible-light-mediated cycloaddition of arenes with an N-N-arenophile and in situ diimide reduction. Subsequent cycloreversion or fragmentation of the arenophile moiety affords 1,3-cyclohexadienes or 1,4-diaminocyclohex-2-enes, compounds that are not synthetically accessible using existing dearomatization reactions. Importantly, this strategy also provides numerous opportunities for further derivatization as well as site-selective functionalization of polynuclear arenes.
