γ-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.

Doped quantum dots for chemo/biosensing and bioimaging

“…290 Use of a polysaccharide-coating is an effective way to improve the biocompatibility of Mn-doped QDs in the cellular environment. Kang et al 291 used g-radiation to graft chitosan on the surface of Mn-doped ZnSe QDs, and found that the synthesized chitosan-coated Mn-doped ZnSe QDs stained cytoplasm but did not enter into nucleus after Hep G2 cells were incubated in the solution of QDs. Chitosan-coated Mn-doped ZnS QDs also show very similar intracellular behavior.…”

Aqueous synthesis of mercaptopropionic acid capped Mn2+-doped ZnSe quantum dots

“…12 In the next year, Norris et al 13 developed an organometallic synthesis method to prepare highquality ZnSe nanocrystals doped with Mn impurities. Then, Dai et al 14 reported the g-radiation synthesis of superparamagnetic CS-ZnSe:Mn nanocrystals which were utilized for biological labeling. Recently, the organometallic synthesis of Mn:ZnSe d-dots achieved a great breakthrough; 5-8 Peng's group decoupled the doping process from nucleation and/or growth, and designed nucleation-doping and growth-doping processes to prepare Mn:ZnSe d-dots and Cu:ZnSe d-dots, respectively.…”

RETRACTED: Investigation on manganese-doped ZnSe QDs prepared from self-assembled template of reverse micelle

“…There have been various synthetic approaches reported in synthesis of doped QDs [16][17][18][19][20][21][22][23][24] and several good reviews or research articles on this subject [11,[25][26][27][28][29][30]. In 2001, Norris et al [16] first demonstrated successful doping of Mn 2 + into ZnSe colloidal nanocrystals through organometallic synthesis at 240-300 1C.…”