Fluorescent and Magnetic Resonance Imaging by Rare Earth Doped Nanoparticles with Garnet Structure
- PDF / 666,133 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 41 Downloads / 200 Views
1064-PP03-06
Fluorescent and Magnetic Resonance Imaging by Rare Earth Doped Nanoparticles with Garnet Structure Ryo Asakura1, Hiroshi Sakane1, Kunihiro Noda1, Tetsuhiko Isobe1, Masahito Morita2,3, and Toshiro Inubushi2 1 Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan 2 Biomedical MR Science Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, 520-2192, Japan 3 PRESTO, JST, 4-1-8, Honcho, Kawaguchi-shi, Saitama, 332-0012, Japan ABSTRACT Yb3+ doped Y3Al5O12 (YAG:Yb3+) nanoparticles are prepared from yttrium acetate tetrahydrate, ytterbium acetate tetrahydrate and aluminum isopropoxide in 1,4-butanediol by autoclave treatment at 300 ºC for 2 h. Moreover, Gd-YAG:Yb3+ nanoparticles are prepared from the mixture of YAG:Yb3+ colloidal solution and gadolinium acetate tetrahydrate by the same autoclave treatment as YAG:Yb3+. Properties of structure, near infrared photoluminescence and magnetic resonance contrast enhancement are characterized for as-prepared and calcined YAG:Yb3+ and Gd-YAG:Yb3+ nanoparticles. INTRODUCTION Utility of luminescent inorganic nanoparticles for fluorescent imaging of biomolecules have advantages over conventional organic dyes in terms of photostability and Stokes shift. Excitation and emission in the near infrared (NIR) region minimize absorption loss by biomolecules and inhibit their autofluorescence [1,2]. Therefore, lanthanides (Ln) doped nanoparticles such as silica-coated LaF3:Ln [2] have been investigated for biological application. Magnetic resonance (MR) imaging is clinically useful. Complexes of paramagnetic Gd3+ with seven unpaired electrons are used as magnetic resonance (MR) contrast agents. Furthermore, dual modal imaging of MR and fluorescence provides complimentary information [3]. Recently, several types of nanoparticles, e.g., the combination between Gd3+ complexes and quantum dots with visible emission [4-7], Gd2O3 doped with green emission center of Tb3+ [8] have been proposed as dual modal probing agents. We have prepared Y3Al5O12:Ce3+ (YAG:Ce3+) nanoparticles conjugated with biotin and demonstrated fluorescent imaging using avidin-biotin interaction [9]. Here we focus on two kinds of rare earth ions, Yb3+ and Gd3+, which provide the functions of NIR fluorescence and MR contrast enhancement, respectively. We synthesize YAG nanoparticles doped with Yb3+ and Gd3+, and characterize their optical and magnetic properties. EXPERIMENT YAG:Yb3+ (nominal composition: (Y0.9Yb0.1)3Al5O12) were synthesized by the following glycothermal method. Yttrium acetate tetrahydrate (6.75 mmol), ytterbium acetate tetrahydrate (0.75 mmol) and aluminum isopropoxide (12.5 mmol) were put into the autoclave (Taiatsu
Techno Corp., TVS-120-N2) containing 63.6 mL 1,4-butanediol (1,4-BD). The sealed autoclave was linearly heated from 25 to 300 ºC for 90 min with stirring at 300 rpm, kept at the same temperature for 2 h. After cooling to room temperature, the obtained YAG:Yb3+ colloidal solution was stood for 1 day to induce the sedime
Data Loading...
