Co-enhancement of fluorescence and singlet oxygen generation by silica-coated gold nanorods core-shell nanoparticle

Abstract

Metal-enhanced fluorescence (MEF) as a newly recognized technology has been attracting considerable attention and is widely used in fluorescence-based technology. In this paper, we reported a novel distance-dependent MEF and metal-enhanced singlet oxygen generation phenomenon based on silica-coated gold nanorods (AuNRs@SiO2) core-shell structure with tetra-substituted carboxyl aluminum phthalocyanine (AlC4Pc) that serve as both fluorophore and photosensitizer. When the AlC4Pc was linked on the surface of AuNRs@SiO2, the fluorescence intensity and singlet oxygen productivity varied with the thickness difference of silica shell from 2.1 to 28.6 nm. The co-enhancement effect reached the maximum of 7-fold and 2.1-fold, respectively, when the separation distance was 10.6 nm. These unique characteristics make the prepared core-shell nanoparticles promising for MEF-based biological imaging and photodynamics therapy.

Toxic effects and biodistribution of ultrasmall gold nanoparticles

“…However, NAA is rather limited in spatial resolution so that quantification of gold is not feasible on a single cell level but requires integration over a larger number of cells. In contrast, ligand shell of AuNPs may directly be traced on the cellular level by utilizing fluorescence quenching (Ke 2014) and/or enhancing effects (Chowdhury 2006). In order to investigate the hypothesized ligand loss of Au1.4MS upon cellular uptake, new phosphine stabilized cytotoxic Au1.4MS have been synthesized bearing a fluorophore, so that fluorescence de-quenching can be utilized to visualize the fate of the ligand.…”

Optical Properties of Hybrid Organic‐Inorganic Materials and their Applications

“…[454] Among the most investigated strategies is the use of core shell nanostructures with metal core and silica based shell, which provides also a good possibility of spacing control between the dyes and the metallic surface. [455][456][457][458][459][460][461][462][463][464][465] The dye can be either directly incorporated in the silica shell during the synthesis of post-grafted at the surface of the silica. M. A. Noginov used this configuration to generate core-shell structure functionalized at the surface by Oregon green 488 fluorophore encapsulated in the outer silica shell.…”

Graphene Oxide Wrapped SiO2/TiO2 Hollow Nanoparticles Loaded with Photosensitizer for Photothermal and Photodynamic Combination Therapy

“…A NIR laser and a LED light were used as the light sources in this study because of their tissue penetration properties and safety toward the cells. To confirm the photodynamic activity of GO‐HNP‐PpIX, 1 O 2 generation was detected by a chemical trapping method with 9,10‐anthracenediyl bis(methylene)dimalonic acid (ABDA) . ABDA reacts with the generated 1 O 2 and causes a decrease in the ABDA absorption band at λ =380 nm .…”