Bio-conjugation Of Caf_2:eu/chitosan Nanoparticles With Bsa And Photoluminescent Properties

摘要

CaF_2:Eu nanoparticles capped with chitosan and bio-conjugation of CaF_2:Eu/chitosan nanoparticles with bovine serum albumin (BSA) were synthesized via micro-emulsion method. As a surfactant, chitosan was employed to cap the nanoparticles during the synthesis process and provided functional groups, such as amino group for further bio-conjunction with BSA. CaF_2:Eu and CaF_2:Eu/chitosan-BSA nanoparticles were characterized by means of X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), ultraviolet spectrophotometer (UV), infrared spectrophotometer (IR) and photoluminescence spectrophotometer (PL). The XRD results indicated that the CaF_2:Eu and CaF_2:Eu/chitosan-BSA nanoparticles have crystallized well and the average sizes were about 16 and 19 nm, respectively. Images of FE-SEM showed that the average grain sizes of the CaF_2:Eu and bio-conjunction of CaF_2:Eu/chitosan nanoparticles with BSA were about 19 andrn20 nm. The patterns of UV spectra and IR spectra showed that BSA was linked to CaF_2:Eu/chitosan nanoparticles. In the emission spectrum of the CaF_2:Eu/chitosan-BSA nanoparticles, characteristic emission peaks of Eu~(3+) within the wavelength ranging from 500 to 700 nm were observed, corresponding to the transitions from the excited ~5D_0 levels to ~7F_J levels. This confirmed that the Eu~(3+)dopant ion is located in a Ca~(2+) crystal site with Td symmetry.