Tuning Plasmonic Enhancement of Single Nanocrystal Upconversion Luminescence by Varying Gold Nanorod Diameter

Abstract

Plasmonic enhancement induced by metallic nanostructures is an effective strategy to improve the upconversion efficiency of lanthanide-doped nanocrystals. It is demonstrated that plasmonic enhancement of the upconversion luminescence (UCL) of single NaYF :Yb /Er /Mn nanocrystal can be tuned by tailoring scattering and absorption cross sections of gold nanorods, which is synthesized wet chemically. The assembly of the single gold nanorod and single upconversion nanocrystal is achieved by the atomic force microscope probe manipulation. By selecting two kinds of gold nanorods with similar longitudinal surface plasmon resonance wavelength but different diameters (27.3 and 46.7 nm), which extinction spectra are separately dominant by the absorption and scattering, the maximum UCL enhancement by a factor of 110 is achieved with the 46.7 nm-diameter gold nanorod, while it is 19 for the nanorod with the diameter of 27.3 nm. Such strong enhancement with the larger gold nanorod is due to stronger scattering ability and greater extent of the near-field enhancement. The enhanced UCL shows a strong dependence on the excitation polarization relative to the nanorod long axis. Time-resolved measurements and finite-difference time-domain simulations unveil that both excitation and emission processes of UCL are accelerated by the nanorod plasmonic effect.

Enhanced upconversion fluorescent probe of single NaYF4:Yb3+/Er3+/Zn2+ nanoparticles for copper ion detection

“…In order to improve the luminescence intensity and detecting efficiency, researchers have proposed a variety of methods, such as ions co-doping, the introduction of transition metal ions, core-shell coating, plasmon resonance enhancement and so on. [21][22][23][24][25] Many studies have been reported on the introduction of smaller radius ions (Li + , Mn 2+ , Mg 2+ , etc.) [26][27][28] in UCNPs to enhance the upconversion emission, but few studies on the introduction of Zn 2+ ions into the rare-earth doped hexagonal phase NaYF 4 nanoparticles are presented.…”

Preparation and photoluminescence enhancement of Au nanoparticles with ultra‐broad plasmonic absorption in glasses

“…At present, a variety of methods such as tailoring the rare earth doping level, a host matrix selection with low phonon energy, photonic crystals surface effect have been developed to enhance the UCL . The collective oscillations of the free electrons of metal nanoparticles (NPs) can generate the localized plasmonic resonance absorption (LSPR), which offers another effective way to enhance the UCL efficiency of rare‐earth doped materials . At present, the LSPR of the noble silver and gold NPs have been widely used to enhance the UCL of rare‐earth doped NPs .…”

Plasmon-enhanced fluorescence of submonolayer porphyrins by silver-polymer core-shell nanoparticles

“…In our previous work, surface plasmon resonance wavelengths and NPs sizes could be well controlled to obtain the single nanocrystal upconversion luminescence enhancement [22]. Porphyrin molecules were chosen here as emitters because of their famous wide range of optical related applications [23,24] by constructing functional structures as building blocks [25].…”