Fabrication and fluorescence properties of multilayered core–shell particles composed of quantum dot, gadolinium compound, and silica

• Published in: Journal of materials science Vol. 47; no. 4; pp. 1852 - 1859
• Main Authors: Kobayashi, Yoshio, Nozawa, Takuya, Nakagawa, Tomohiko, Gonda, Kohsuke, Takeda, Motohiro, Ohuchi, Noriaki
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2012; Springer; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Coating; Coatings; Crystallography and Scattering Methods; Ethanol; Ethyl alcohol; Fluorescence; Gadolinium; Gadolinium compounds; Magnetic resonance imaging; Materials Science; Nanoparticles; Polymer Sciences; Polyvinylpyrrolidone; Precipitation (Meteorology); Quantum dots; Shells; Silica; Silicon; Silicon compounds; Silicon dioxide; Sodium hydroxide; Solid Mechanics; Urea; Show Transmission Electron Microscope Image; Shell Particle; Homogeneous Precipitation Method; Gadolinium Complex; TEOS Concentration
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-011-5972-z

A preparation method for multilayered quantum dot/silica/gadolinium compound/silica (QD/Si/Gd/Si) core–shell particles is proposed. Silica (Si)-coated quantum dot (QD/Si) core–shell particles were prepared by a Stöber method at room temperature in water/ethanol solution with TEOS and NaOH in the presence of QD nanoparticles. Succeeding gadolinium compound (Gd)-coating of the QD/Si core–shell particles was performed by a homogeneous precipitation method using Gd(NO 3 ) 3 , urea, and polyvinylpyrrolidone in the presence of the QD/Si particles, which resulted in production of multilayered QD/silica/gadolinium compound (QD/Si/Gd) core–shell particles. For Si-coating of the QD/Si/Gd particles, the Stöber method was performed at room temperature in water/ethanol solution with TEOS and NaOH in the presence of the QD/Si/Gd particles. Consequently, Si-coated QD/Si/Gd, i.e., multilayered QD/Si/Gd/Si, core–shell particles were obtained. The QD/Si/Gd/Si particles revealed strong fluorescence, which was almost comparable to the QD particles with no shells. These particles are expected to be harmless to living bodies, and have dual functions of magnetic resonance imaging and fluorescence.