Publications by authors named "Fan-Li Zhang"

3 Publications

  • Page 1 of 1

Shell-Isolated Nanoparticle-Enhanced Luminescence of Metallic Nanoclusters.

Anal Chem 2020 05 28;92(10):7146-7153. Epub 2020 Apr 28.

College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Energy, Department of Physics, Xiamen University, Xiamen 361005, China.

Metallic nanoclusters (NCs) have molecular-like structures and unique physical and chemical properties, making them an interesting new class of luminescent nanomaterials with various applications in chemical sensing, bioimaging, optoelectronics, light-emitting diodes (LEDs), etc. However, weak photoluminescence (PL) limits the practical applications of NCs. Herein, an effective and facile strategy of enhancing the PL of NCs was developed using Ag shell-isolated nanoparticle (Ag SHIN)-enhanced luminescence platforms with tuned SHINs shell thicknesses. 3D-FDTD theoretical calculations along with femtosecond transient absorption and fluorescence decay measurements were performed to elucidate the enhancement mechanisms. Maximum enhancements of up to 231-fold for the [AuAg(C≡CBu)] cluster and 126-fold for DNA-templated Ag NCs (DNA-Ag NCs) were achieved. We evidenced a novel and versatile method of achieving large PL enhancements with NCs with potential for practical biosensing applications for identifying target DNA in ultrasensitive surface analysis.
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http://dx.doi.org/10.1021/acs.analchem.0c00600DOI Listing
May 2020

Elucidating Molecule-Plasmon Interactions in Nanocavities with 2 nm Spatial Resolution and at the Single-Molecule Level.

Angew Chem Int Ed Engl 2019 Aug 2;58(35):12133-12137. Epub 2019 Aug 2.

MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid, Surfaces,iChEM, College of Chemistry and Chemical Engineering, College of Materials, Xiamen University, Xiamen, 361005, China.

The fundamental understanding of the subtle interactions between molecules and plasmons is of great significance for the development of plasmon-enhanced spectroscopy (PES) techniques with ultrahigh sensitivity. However, this information has been elusive due to the complex mechanisms and difficulty in reliably constructing and precisely controlling interactions in well-defined plasmonic systems. Herein, the interactions in plasmonic nanocavities of film-coupled metallic nanocubes (NCs) are investigated. Through engineering the spacer layer, molecule-plasmon interactions were precisely controlled and resolved within 2 nm. Efficient energy exchange interactions between the NCs and the surface within the 1-2 nm range are demonstrated. Additionally, optical dressed molecular excited states with a huge Lamb shift of ≈7 meV at the single-molecule (SM) level were observed. This work provides a basis for understanding the underlying molecule-plasmon interaction, paving the way for fully manipulating light-matter interactions at the nanoscale.
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http://dx.doi.org/10.1002/anie.201906517DOI Listing
August 2019

Shell-Isolated Nanoparticle-Enhanced Phosphorescence.

Anal Chem 2018 09 5;90(18):10837-10842. Epub 2018 Sep 5.

MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, Department of Physics, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.

The emerging field of plasmonics has promoted applications of optical technology, especially in plasmon-enhanced spectroscopy (PES). However, in plasmon-enhanced fluorescence (PEF), "metal loss" could significantly quench the fluorescence during the process, which dramatically limits its applications in analysis and high-resolution imaging. In this report, silver core silica shell-isolated nanoparticles ([email protected] NPs or SHINs) with a tunable thickness of shell are used to investigate the interactions between NPs and emitters by constructing coupling and noncoupling modes. The plasmonic coupling mode between [email protected] NPs and Ag film reveals an exceeding integrating spectral intensity enhancement of 330 and about 124 times that of the radiative emission rate acceleration for shell-isolated nanoparticle enhanced phosphorescence (SHINEP). The experimental findings are supported by theoretical calculations using the finite-element method (FEM). Hence, the SHINEP may provide a novel approach for understanding the interaction of plasmon and phosphorescence, and it holds great potential in surface detection analysis and singlet-oxygen-based clinical therapy.
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http://dx.doi.org/10.1021/acs.analchem.8b02109DOI Listing
September 2018
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