Fe doped CdTeS magnetic quantum dots for bioimaging

Abstract

A facile synthesis of 3-6 nm, water dispersible, near-infrared (NIR) emitting, quantum dots (QDs) magnetically doped with Fe is presented. Doping of alloyed CdTeS nanocrystals with Fe was achieved in situ using a simple hydrothermal method. The magnetic quantum dots (MQDs) were capped with NAcetyl-Cysteine (NAC) ligands, containing thiol and carboxylic acid functional groups to provide stable aqueous dispersion. The optical and magnetic properties of the Fe doped MQDs were characterized using several techniques. The synthesized MQDs are tuned to emit in the Vis-NIR (530-738 nm) wavelength regime and have high quantum yields (67.5-10%). NIR emitting (738 nm) MQDs having 5.6 atomic% Fe content exhibited saturation magnetization of 85 emu/gm[Fe] at room temperature. Proton transverse relaxivity of the Fe doped MQDs (738 nm) at 4.7 T was determined to be 3.6 mM−1s−1. The functional evaluation of NIR MQDs has been demonstrated using phantom and in vitro studies. These water dispersible, NIR emitting and MR contrast producing Fe doped CdTeS MQDs, in unagglomerated form, have the potential to act as multimodal contrast agents for tracking live cells.

Haemostatic Nanoparticles-Derived Bioactivity of from Selaginella tamariscina Carbonisata

“…The N1s spectrum ( Figure 4d) was resolved into two peaks at 399.8 and 401.2 eV. These peaks corresponded to C-N-C and (C)3-N bonds, respectively [19,20]. The experimental results were consistent with the FT-IR characterisation [21,22].…”

Nanoparticulate Contrast Agents for Multimodality Molecular Imaging

“…Saha et al reported Fe doped CdTeS quantum dots capped with N -acetyl-cysteine (NAC) ligands. 57 Due to the concern about potential leakage of highly toxic cadmium ions, researchers have attempted to synthesis non-cadmium based QD (e.g., ZnO, [58][59][60] ZnS, 61 62 InP, 63 64 CuInS 2 65 ), and many of those QDs are also used to produce multimodality probes. Lin et al reported a CuInS 2 /Zn 1−x Mn x S Core/Shell QDs.…”

One-pot aqueous synthesis of gadolinium doped CdTe quantum dots with dual imaging modalities

“…Since Schwartz et al reported the synthesis of Co 2+ and Ni 2+ doped ZnO nanocrystals in 2003, [30] more and more magnetic ions doped QDs have been prepared as dual-modal agents in the last two decades, such as Ni-doped CdTeSe/CdS, [31] Fe-doped CdTeS, [32] Gd-doped CdSe, [27] Mn-doped CdSe, [33], Mn-doped CdS/ZnS [34], Gd-doped ZnO [29], Gd-doped ZnAgInS 3 [35] and Gd-doped CuInS/ZnS [36]. However, most of these magnetic QDs were prepared in organic phase and further surface modifications were necessary to make them water -soluble, which are time-consuming and always lead to the decrease of quantum yields.…”