Synthesis and Characterization of Functionalized Magnetic Nanoparticles for the Detection of PesticideDSchool of Material Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi City, Ishikawa 923-1292, Japan

摘要

We synthesized magnetic nanoparticles (MNPs) by mixing aqueous solutions of 3d transition metal chlorides (MC12 · nH2O) and a sodium metasilicate nonahydrate (Na2SiO3 · 9H2O) in order to produce monodispersed MNPs in a single step. The particle size can be controlled by adjusting the annealing temperature. We characterized the MNPs by X-ray diffraction (XRD), superconducting quantum interference device (SQUID), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and zeta-potential measurement. Paramagnetic and superparamagnetic behaviors were found for the obtained samples depending on the particle size (d = 3.0-4.6 nm). The synthesized MNPs could be modified with the amino-, phenyl-, and carboxy- groups on MNPs' surface by silanization procedure, respectively. The purpose of functionalizing the surface of the nanoscale magnetic particles was to realize subsequent capture and detection with desired other molecules by nanoparticle assisted laser ionization/desorption mass spectrometry.