Carbon Dots/Iron Oxide Nanoparticles with Tuneable Composition and Properties.

Joanna D Stachowska,Monika B Gamża,Ella N Gibbons,Claire Mellor,Tomasz Strączek,Antonios Kelarakis,Marta J Krysmann,Anna Szwajca,Elżbieta Gumieniczek-Chłopek,Czesław Kapusta

doi:10.3390/nano12040674

Abstract

We present a simple strategy to generate a family of carbon dots/iron oxide nanoparticles (C/Fe-NPs) that relies on the thermal decomposition of iron (III) acetylacetonate in the presence of a highly fluorescent carbon-rich precursor (derived via thermal treatment of ethanolamine and citric acid at 180 °C), while polyethylene glycol serves as the passivation agent. By varying the molar ratio of the reactants, a series of C/Fe-NPs have been synthesized with tuneable elemental composition in terms of C, H, O, N and Fe. The quantum yield is enhanced from 6 to 9% as the carbon content increases from 27 to 36 wt%, while the room temperature saturation magnetization is improved from 4.1 to 17.7 emu/g as the iron content is enriched from 17 to 31 wt%. In addition, the C/Fe-NPs show excellent antimicrobial properties, minimal cytotoxicity and demonstrate promising bioimaging capabilities, thus showing great potential for the development of advanced diagnostic tools.

Highlights

Publisher’s Note: MDPI stays neutralSuperparamagnetic iron oxide nanoparticles (Fe-NPs) with sizes below 20 nm have been widely explored in a wide range of biomedical applications, including magnetically controlled gene and drug delivery [1,2], hyperthermia treatment [3], bioseparation of cells [4], cell tracking and tissue repair [1], magnetic resonance imaging (MRI) [5,6], biosensors [7], diagnosis and treatment of bacterial infections [8]
We present a simple strategy to synthesize a series of C/Fe-NPs with varying chemical composition that exhibit tuneable magnetization coupled with superior wavelength-dependent optical properties, bioimaging capabilities, non-toxic nature and antimicrobial activity
In this study CNP180 was subjected to pyrolysis at 230 ◦ C, but in the presence of varying amounts of Fe(acac)3 and upon the addition of Polyethylene glycol 400 (PEG400) in order to synthesize a series of well-defined C/Fe-NPs

Summary

Introduction

Superparamagnetic iron oxide nanoparticles (Fe-NPs) with sizes below 20 nm have been widely explored in a wide range of biomedical applications, including magnetically controlled gene and drug delivery [1,2], hyperthermia treatment [3], bioseparation of cells [4], cell tracking and tissue repair [1], magnetic resonance imaging (MRI) [5,6], biosensors [7], diagnosis and treatment of bacterial infections [8]. Accurate control of the reaction conditions (nature of organometallic reactants, iron salts, surfactants, solvents, temperature, duration), purification protocols and passivation strategies can lead to tailor-made Fe-NPs with narrow size distribution [13]. Surfactants and macromolecules are physically adsorbed or chemically attached to Fe-NPs, while passivating layers based on precious with regard to jurisdictional claims in published maps and institutional affiliations

Methods

Results

Conclusion