Two-photon fluorescence imaging super-enhanced by multishell nanophotonic particles, with application to subcellular pH.
Small
; 8(14): 2213-21, 2012 Jul 23.
Article
en En
| MEDLINE
| ID: mdl-22517569
A novel nanophotonic method for enhancing the two-photon fluorescence signal of a fluorophore is presented. It utilizes the second harmonic (SH) of the exciting light generated by noble metal nanospheres in whose near-field the dye molecules are placed, to further enhance the dye's fluorescence signal in addition to the usual metal-enhanced fluorescence phenomenon. This method enables demonstration, for the first time, of two-photon fluorescence enhancement inside a biological system, namely live cells. A multishell hydrogel nanoparticle containing a silver core, a protective citrate capping, which serves also as an excitation quenching inhibitor spacer, a pH indicator dye shell, and a polyacrylamide cladding are employed. Utilizing this technique, an enhancement of up to 20 times in the two-photon fluorescence of the indicator dye is observed. Although a significant portion of the enhanced fluorescence signal is due to one-photon processes accompanying the SH generation of the exciting light, this method preserves all the advantages of infrared-excited, two-photon microscopy: enhanced penetration depth, localized excitation, low photobleaching, low autofluorescence, and low cellular damage.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Microscopía de Fluorescencia por Excitación Multifotónica
/
Nanopartículas
/
Imagen Óptica
Límite:
Humans
Idioma:
En
Revista:
Small
Asunto de la revista:
ENGENHARIA BIOMEDICA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Alemania