Distance-dependent plasmon-enhanced fluorescence of upconversion nanoparticles using polyelectrolyte multilayers as
Ai Ling Feng1, Min Li You1, Limei Tian2
11] The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P.R. China [2] Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P.R. China.
Scientific Reports
|January 15, 2015
Summary
Lanthanide-doped upconversion nanoparticles (UCNPs) show promise for bioimaging, but low fluorescence requires enhancement. This study achieved a 22.6-fold fluorescence boost using gold nanorods as nanoantennae, optimizing distance for improved bioapplication potential.
Area of Science:
- Nanotechnology
- Biophotonics
- Materials Science
Background:
- Lanthanide-doped upconversion nanoparticles (UCNPs) offer unique near-infrared to visible light conversion for bioapplications.
- Low quantum yield of UCNPs necessitates strategies for fluorescence enhancement.
- Plasmon nanostructures can amplify fluorescence by concentrating electric fields.
Purpose of the Study:
- To develop a plasmon-enhanced fluorescence system for UCNPs.
- To precisely control the distance between UCNPs and gold nanorods (AuNRs) using polyelectrolyte multilayers.
- To optimize the enhancement by tuning AuNRs' localized surface plasmon resonance (LSPR).
Main Methods:
- Layer-by-layer assembly of polyelectrolyte multilayers to create tunable spacers.
- Synthesis of gold nanorods (AuNRs) with controlled aspect ratios.
- Integration of UCNPs with AuNRs at precise distances.
- Characterization of optical properties and fluorescence enhancement.
Main Results:
- Achieved precise distance tuning between UCNPs and AuNRs using polyelectrolyte spacers.
- Matched the LSPR of AuNRs to the 980 nm excitation wavelength of UCNPs.
- Demonstrated a maximum fluorescence enhancement of 22.6-fold with an 8 nm spacer thickness.
- Validated the effectiveness of the plasmonic enhancement strategy.
Conclusions:
- Developed a novel plasmon-enhanced fluorescence system for UCNPs.
- Precise control over nanoparticle spacing is crucial for maximizing fluorescence enhancement.
- This hybrid nanostructure platform holds significant potential for advanced bioimaging applications.
