Bulk and single-molecule characterization of an improved molecular beacon utilizing H-dimer excitonic behavior.
J Phys Chem B
; 111(28): 7929-31, 2007 Jul 19.
Article
em En
| MEDLINE
| ID: mdl-17583944
ABSTRACT
Pairs of fluorophores in close proximity often show self-quenching of fluorescence by the well-known H-dimer mechanism. We use a pair of fluorophores in the new dicyanomethylenedihydrofuran (DCDHF) dye family in the design and characterization of a new fluorescent probe for nucleic acid detection, which we refer to as a self-quenched intramolecular dimer (SQuID) molecular beacon (MB). We obtain a quenching efficiency of 97.2%, higher than the only other reported value for a MB employing fluorophore self-quenching by H-dimer formation. Furthermore, the excellent single-molecule (SM) emitter characteristics of the DCDHF dyes allow observation of individual SQuID MB-target complexes immobilized on a surface, where the doubled SM emission intensity of our target-bound beacon ensures a higher signal-to-background ratio than conventional fluorophore-quencher MBs. Additional advantages of the SQuID MB are single-pot labeling, visible colorimetric detection of the target, and intrinsic single-molecule two-step photobleaching behavior, which offers a specific means of discriminating between functional MBs and spurious fluorescence.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ácidos Nucleicos
/
Sondas de Oligonucleotídeos
/
Corantes Fluorescentes
/
Furanos
/
Nitrilas
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article