Single-molecule characterization of a bright and photostable deep-red fluorescent squaraine-figure-eight (SF8) dye.

ABSTRACT: Squaraine Figure Eight (SF8) dyes are a unique class of deep-red fluorescent dyes with self-threaded molecular architecture that provides structural rigidity while simultaneously encapsulating and protecting the emissive fluorochrome. Previous cell microscopy and bulk phase studies of SF8 dyes indicated order of magnitude enhancements in photostability over conventional pentamethine cyanine dyes such as Cy5. Studies conducted at the single molecule level now reveal that these ensemble level enhancements carry over to the single molecule level in terms of enhanced emission quantum yields, longer times to photobleaching, and enhanced total photon yields. When compared to Cy5, the SF8-based dye SF8(D4)₂ possesses a three-fold larger single molecule emission quantum yield, exhibits

SUBMITTER: Kniazev K 

PROVIDER: S-EPMC9835836 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature