Folic acid-conjugated core/shell ZnS:Mn/ZnS quantum dots as targeted probes for two photon fluorescence imaging of cancer cells.
This work presents a novel approach to producing water soluble manganese-doped core/shell ZnS/ZnS quantum dots (ZnS:Mn/ZnS). The Mn-doped ZnS core was prepared through a nucleation doping strategy and a ZnS shell was grown on ZnS:Mn d-dots by decomposition of Zn(2+)-3-mercaptopropionic acid (MPA) complexes at 100 °C. It was found that the Mn2+(4)T1→6A1 fluorescence emission at ∼590 nm significantly increased after growth of the shell when the Mn2+ doping content was 4.0 at.%. A photoluminescence quantum yield of ∼22% was obtained for core/shell nanocrystals. The nanoparticles were structurally and compositionally characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and dynamic light scattering. The surface MPA molecules favor the dispersion of ZnS:Mn/ZnS QDs in aqueous media and make possible conjugation with targeting folic acid molecules. The folate receptor-mediated delivery of folic acid-conjugated ZnS:Mn/ZnS QDs was demonstrated using confocal microscopy with biphotonic excitation. Bare and folate-conjugated QDs exhibit only weak cytotoxicity towards folate receptor-positive T47D cancer cells and MCF-7 cells, used as a reference, at high concentrations (mmolar range) after 72h incubation.
Geszke
Malgorzata
M
Laboratoire Réactions et Génie des Procédés, UPR 3349, Nancy-University, CNRS, 1 Rue Grandville, 54001 Nancy Cedex, France.
Murias
Marek
M
Balan
Lavinia
L
Medjahdi
Ghouti
G
Korczynski
Jaroslaw
J
Moritz
Michal
M
Lulek
Janina
J
Schneider
Raphaël
R
D045744:Cell Line, Tumor; D005456:Fluorescent Dyes / Q000737:chemistry*; D005492:Folic Acid / Q000737:chemistry*; D006801:Humans; D008274:Magnesium / Q000737:chemistry*; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009369:Neoplasms / Q000473:pathology*; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry*; D014961:X-Ray Diffraction; D017967:Zinc Compounds / Q000737:chemistry*
D005456:Fluorescent Dyes; D013440:Sulfides; D017967:Zinc Compounds; D005492:Folic Acid; D008274:Magnesium; C031238:zinc sulfide