Novel multifunctional nanocomposites: magnetic mesoporous silica nanospheres covalently bonded with near-infrared luminescent lanthanide complexes

Langmuir. 2010 Mar 2;26(5):3596-600. doi: 10.1021/la903008z.

Abstract

In this paper, we report the fabrication and characterization of magnetic mesoporous silica nanospheres covalently bonded with near-infrared (NIR) luminescent lanthanide complexes [denoted as Ln(DBM)(3)phen-MMS (Ln = Nd, Yb)]. Ln(DBM)(3)phen-MMS (Ln = Nd, Yb) nanospheres with an average size of 80-130 nm were synthesized via incorporation of the chelate ligand 5-[N,N-bis-3-(triethoxysilyl)propyl]ureyl-1,10-phenanthroline (phen-Si) into the framework of magnetic mesoporous silica (denoted as phen-MMS), followed by introduction of the Ln(DBM)(3)(H(2)O)(2) (Ln = Nd, Yb) complexes into the nanocomposites via a ligand exchange reaction. The morphological, structural, textural, magnetic, and NIR luminescent properties were well-characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N(2) adsorption-desorption, a superconducting quantum interference device (SQUID), and photoluminescence spectra. These nanocomposites, which possess high surface area, high pore volume, and well-defined pore size, exhibit two-dimensional hexagonal (P6mm) mesostructures. After ligand-mediated excitation, Ln(DBM)(3)phen-MMS (Ln = Nd, Yb) nanocomposites exhibit the characteristic NIR emission of Nd(3+) and Yb(3+), respectively. Magnetic measurements reveal that these mulfunctional nanocomposites possess superparamagnetic properties at 300 K. The high magnetization values make the nanocomposites respond to the external magnetic field quickly. Additionally, the results indicate that Nd(DBM)(3)phen-MMS nanocomposites may have potential applications for laser systems or the optical amplifiers operating at 1.3 microm and Yb(DBM)(3)phen-MMS nanocomposites have several advantages for potential applications in drug delivery or optical imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Infrared Rays*
  • Lanthanoid Series Elements / chemistry*
  • Luminescent Agents / chemical synthesis
  • Luminescent Agents / chemistry
  • Magnetics*
  • Microscopy, Electron, Scanning
  • Nanocomposites / chemistry*
  • Nanospheres / chemistry*
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Porosity
  • Scattering, Small Angle
  • Silicon Dioxide / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • X-Ray Diffraction

Substances

  • Lanthanoid Series Elements
  • Luminescent Agents
  • Organometallic Compounds
  • Silicon Dioxide