Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores.

ABSTRACT: The water-soluble, near-IR-emitting DNA-encapsulated silver nanocluster presented herein exhibits extremely bright and photostable emission on the single-molecule and bulk levels. The photophysics have been elucidated by intensity-dependent correlation analysis and suggest a heavy atom effect of silver that rapidly depopulates an excited dark level before quenching by oxygen, thereby conferring great photostability, very high single-molecule emission rates, and essentially no blinking on experimentally relevant time scales (0.1 to >1,000 ms). Strong antibunching is observed from these biocompatible species, which emit >10(9) photons before photobleaching. The significant dark-state quantum yield even enables bunching from the emissive state to be observed as a dip in the autocorrelation cu

SUBMITTER: Vosch T 

PROVIDER: S-EPMC1937515 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature