Fabrication of silk fibroin coated ZnSe : Mn2+ quantum dots under γ-radiation and their magnetic properties

Silk fibroin coated Mn2+-doped ZnSe quantum dots (SF-ZnSe:Mn2+ QDs) were successfully synthesized via a one-step γ-radiation route in an aqueous system at room temperature. The prepared QDs were characterized by transmission electron microscopy (TEM) images, energy dispersion spectroscopy (EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy and superconducting quantum interference device (SQUID) magnetometry. The synthesized QDs were about 5 nm in diameter and had excellent water solubility. These QDs showed strong visible orange luminescence under UV excitation and were shown to have a strong emission peak at around 586 nm and a weak emission peak at around 425 nm. Moreover, the products exhibited excellent superparamagnetic behavior when the temperature was above 10 K. These QDs might afford many potential applications in biomedical and other areas. This method could be conveniently extended to fabricate other nanoparticles coated with silk fibroin.