Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications

Abstract

Biocompatible superparamagnetic iron oxide nanoparticles (NPs) through smart chemical functionalization of their surface with fluorescent species, therapeutic proteins, antibiotics, and aptamers offer remarkable potential for diagnosis and therapy of disease sites at their initial stage of growth. Such NPs can be obtained by the creation of proper linkers between magnetic NP and fluorescent or drug probes. One of these linkers is gold, because it is chemically stable, nontoxic and capable to link various biomolecules. In this study, we present a way for a simple and reliable decoration the surface of magnetic NPs with gold quantum dots (QDs) containing more than 13.5% of Au+. Emphasis is put on the synthesis of magnetic NPs by co-precipitation using the amino acid methionine as NP growth-stabilizing agent capable to later reduce and attach gold species. The surface of these NPs can be further conjugated with targeting and chemotherapy agents, such as cancer stem cell-related antibodies and the anticancer drug doxorubicin, for early detection and improved treatment. In order to verify our findings, high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), FTIR spectroscopy, inductively coupled plasma mass spectroscopy (ICP-MS), and X-ray photoelectron spectroscopy (XPS) of as-formed CoFe2O4 NPs before and after decoration with gold QDs were applied.

Band gap engineering of ZnO by amino acid capping for optoelectronic and energy applications

“…The increase in band gap in case of ZnO-L-Ala attributes to the bonding between COO group of alanine and ZnO surface causing strain upon NH 3 + group. 28 The lattice strain in L-Ala due to surface bonding between ZnO and -COO is around 0.09 eV as reported in the literature 28 Figure 4C, it can be inferred that ZnO-D-Ala and ZnO-DL-Ala has large crystallite size with less band gap value of 2.85 eV, whereas other ZnO-AA complexes possess small crystallite size with widened band gap than ZnO NRs.…”

Investigations on the Interfacial Tension Induced Self‐Assembly in Tuning the 2D Morphology of Polypyrrole at Water/Chloroform Interface

“…The peaks at 84.0 eV (4f 7/2 ) and 87.7 eV (4f 5/2 ) corresponds to metallic gold while less intense peaks at 85.58 and 89.47 eV corresponds to Au + . [65] In Figure 4d3, the presence of three types of chorine moieties shows the pristine state of PPy chains in PPy/Cl − . [60] The peaks at 197.…”

Novel Nanocarriers for Ethnopharmacological Formulations

“…Patricia et al developed three different lignin nanoparticles which show better stability, biocompatibility, uniform dispersity, ability to load poorly soluble drugs, good cellular interaction and sustained drug release for disease diagnosis and therapy [19]. Jagminas et al reported a novel method to synthesise methionine mediated super paramagnetic Cobalt ferrite nanoparticle linked with gold quantum dots which has promising application in targeted drug delivery [20]. Chen et al inspected a pH-sensitive drug release system for targeting CD44 receptor using doxorubicin conjugated mesoporous silica nanoparticles which exhibited improved drug effectiveness and better stability at functional pH for novel preparation of drug delivery systems [21].…”