Work

Ultra-photostable DNA FluoroCubes: Mechanism of Photostability and Compatibility with FRET and Dark Quenching

Year: 2022

Type: article

Abstract: DNA-based FluoroCubes were recently developed as a solution to photobleaching, which is a ubiquitous limitation of fluorescence microscopy ( Niekamp;; Stuurman;; Vale Nature Methods, 2020 ). FluoroCubes, which are not as compact ∼4 × 4 × 5.4 nm 3 four-helix bundles coupled to ≤6 fluorescent dyes, remain fluorescent up to ∼50× longer than single dyes and emit up to ∼40× as many photons. The current work answers two important questions about FluoroCubes. First, what is the mechanism by which photostability is enhanced? Second, are FluoroCubes compatible with Förster resonance energy transfer (FRET) and similar techniques? We use single particle photobleaching studies to show that photostability arises through interactions between the fluorophores and the four-helix DNA bundle. Supporting this, we discover that smaller ∼4 × 4 × 2.7 nm 3 FluoroCubes also confer ultraphotostability. However, we find that certain dye–dye interactions negatively impact FluoroCube performance. Accordingly, 4-dye FluoroCubes lacking these interactions perform better than 6-dye FluoroCubes. We also demonstrate that FluoroCubes are compatible with FRET and dark quenching applications.

Source: Nano Letters

DOI: 10.1021/acs.nanolett.2c01757