Fabrication of Ag@SiO₂@Y₂O₃:Er Nanostructures for Bioimaging: Tuning of the Upconversion Fluorescence with Silver Nanoparticles

Abstract

We demonstrated that the nanostructures comprising silver cores and dense layers of Y(2)O(3):Er separated by a silica shell are an excellent model system to study the interaction between upconversion materials and metals in nanoscale. This architecture allows for versatile control of the Y(2)O(3):Er-metal interaction through control of the silica dielectric spacer thickness and the metal-core size. Finally, the nanoparticles are potentially interesting as fluorescent labels in, for instance (single particle), imaging experiments or bioassays which require low background or tissue penetrating wavelengths.

Facile Synthesis of Yolk–Shell Structured Inorganic–Organic Hybrid Spheres with Ordered Radial Mesochannels

“…[ 13,14 ] Generally, yolk-shell structures can be prepared based on a template-assisted approach, in which the core particle is coated with double shells with different materials and then the inner shell is selectively removed by dissolution or calcination. [ 10,[15][16][17] However, this method is synthetically challenging, since multistep depositions are often necessary for preparing multilayer structures. Some other strategies based on the mechanisms of Kirkendall effect, [18][19][20][21] galvanic replacement, [ 22,23 ] surfactantinvolved templating, [ 7,24 ] and partial removal of the core or the shell from core-shell nanoparticles [ 25,26 ] have also been developed to fabricate yolk-shell structures.…”

White-light upconversion emission of lanthanide double-doped oxide nanoparticles via defect state luminescence of ZnO

“…The doping of Ln 3+ ions can convert the near-infrared (NIR) into visible light. The NIR excitation can penetrate the skin, which has potential biological applications, such as bioimaging and multifunctional biological probes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The white UCL has a broad range of emission wavelengths, including blue, green, and red emissions, generating a large library of spectral region that can be used for multiplexed biological labeling and encoding [16,17].…”

Local Field Modulation Induced Three‐Order Upconversion Enhancement: Combining Surface Plasmon Effect and Photonic Crystal Effect

“…[ 8,13,14 ] Attempts to solve this problem include the searching for more effi cient hosts, [ 7 ] coating nanocrystals with an inert/active shell to minimize surface quenching, [ 15 ] or using organic antenna/noble metal-nanostructures to enhance the local optical fi eld by surface plasmon. [ 16,17 ] Plasmonic modulation of metal nanoparticles is a promising method for improving UCL of nanophosphors. [16][17][18][19][20] Plasmonic nanostructures can concentrate the incoming light into a strong localized electric fi eld distributed within the subwavelength regions close to the surface of the nanostructures.…”

“…[ 16,17 ] Plasmonic modulation of metal nanoparticles is a promising method for improving UCL of nanophosphors. [16][17][18][19][20] Plasmonic nanostructures can concentrate the incoming light into a strong localized electric fi eld distributed within the subwavelength regions close to the surface of the nanostructures. The fi eld enhancement is a near-fi eld effect that decays nearly exponentially away from the metal surface.…”