title: Gamma-radiation synthesis and properties of superparamagnetic CS-ZnSe:Mn nanocrystals for biological labeling.
abstract: Chitosan coated ZnSe:Mn (CS-ZnSe:Mn) nanocrystals were successfully synthesized in aqueous system through a gamma-radiation route at room temperature under ambient pressure. The structure and properties of nanocrystals were investigated with transmission electron microscope (TEM), fourier transform infrared spectrometer (FT-IR), ultraviolet-visible (UV-vis) spectrometer, photoluminescence emission (PL) spectra, X-ray Diffraction (XRD) and energy dispersion spectrum (EDS). Results showed that the diameter of these nanocrystals was about 4 nm with narrow size distribution. With the increase of doped Mn2+ concentration, strong emission peak at 610 nm was observed besides the weak emission peak at 425 nm since the non-radiative transition of 4T1(4G)-6A1(6S) level, resulting the transfer of fluorescence color from blue to orange. Moreover, analysis of SQUID magnetometer indicated that the nanocrystals were superparamagnetic with a saturation magnetization of 1.7 emu/g and a Curie-Weiss temperature of 14-15 K. Hep G2 cells were incubated in solution of nanocrystals and results showed that the synthesized nanocrystals could stain cytoplasm but could not enter into nucleus.
authors.affiliation: Medical Physics Center College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Kang
authors.forename: Shu-Quan
authors.initials: SQ
authors.lastname: Chang
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Yao-Dong
authors.initials: YD
authors.lastname: Dai
authors.forename: Da
authors.initials: D
authors.lastname: Chen
mesh_terms: D045744:Cell Line, Tumor; D048271:Chitosan / Q000737:chemistry*; D003460:Crystallization; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D005720:Gamma Rays; D006801:Humans; D008280:Magnetics; D008345:Manganese / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D018036:Selenium Compounds; D017967:Zinc Compounds; D008345:Manganese; D048271:Chitosan