Gadolinium-doped Cu-In-Zn-S quantum dots: one-pot aqueous synthesis and multimodal bioimaging

We report a one-pot method to directly synthesize magnetic resonance/fluorescence multimodal imaging gadolinium-doped Cu-In-Zn-S quantum dots(GCIZS QDs) in aqueous media by using bio-compatible glutathione (GSH) as capping ligand and stabilizer. The optical features and structure of the GCIZS QDs have been characterized by UV-vis and fluorescence spectroscopy, XRD, TEM, and FT-IR. As a result, The GCIZS QDs possessed a strong fluorescence and r(1) value of 4.015 mM(-1)s(-1) at the Cu/Gd ratio of 1/2. Furthermore, the GCIZS QDs were good water solubility and less cytotoxic up to 250 mu g/mL in HUVEC cells. The red emission GCIZS QDs from the MDA-MB-231cells was clearly observed under microscope. It indicated that the GCIZS QDs present great potential as magnetic resonance / fluorescence multimodal imaging contrast agents for biological labels.