Synthesis of Iron Oxide/Gold Composite Nanoparticles Using Polyethyleneimine as a Polymeric Active Stabilizer for Development of a Dual Imaging Probe

Abstract

The combination of magnetic and plasmonic properties using iron oxide/gold nanocomposite particles is crucial for the development of multimodal molecular imaging probes. In this study, iron oxide/gold composite nanoparticles (NanoIOGs) were synthesized via the on-site reduction of an Au precursor salt by polyethyleneimine (PEI) molecules attached to iron oxide nanoparticles (IONPs), and they were employed in magnetic resonance and dark-field microscope imaging. PEI is considered as a polymeric active stabilizer (PAS), acting as a reducing agent for the synthesis of Au and a dispersant for nanoparticles. When the IONPs prepared at the PEI concentration of 0.02 wt. % were used for the NanoIOG synthesis, Au nanoseeds were formed around the IONPs. The alloy clusters of IONPs/Au crystals were produced with further reduction depending on PEI concentration. The NanoIOGs exhibited superparamagnetism in a magnetic field and plasmonic response in a dark-field (DF) microscope. The sizes, morphologies, magnetizations, and r2 relaxivities of NanoIOGs were affected significantly by the amount of PEI added during the NanoIOG synthesis. It is suggested that the PAS-mediated synthesis is simple and effective, and can be applied to various nanostructured Au-metal alloys.

Plasmonic Sensor Based on Interaction between Silver Nanoparticles and Ni2+ or Co2+ in Water

“…The huge development of materials science, nanoscience, and nanomaterials technology has led to the synthesis and engineerization of several nanostructures (metallic and non) used in different fields such as biomedicine [ 1 , 2 ], biotechnology [ 3 , 4 ], energy [ 5 , 6 , 7 , 8 ], optics, and optoelectronics [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Recently, sensors based on different nanosized materials have been developed, achieving a high sensitivity and selectivity [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

Light-Interacting iron-based nanomaterials for localized cancer detection and treatment

“…Hence, nanoparticle complexes made of Au nano-seeds organized at IBN surface were brought into the presence of human fibroblast cells. It was possible to observe assemblies of these IBN in these cells using a dark-field microscope, apparently with a better resolution than the bright field microscope although this aspect was not discussed in this study, [109].…”

Theranostics and contrast agents for magnetic resonance imaging

“…Indeed, MNPs need to be coated with polymers and peptides to stabilize them and enhance their biocompatibility. Various polymers such as poly ethylene glycol(PEG) [ 66 ], dextran [ 67 ], chitosan [ 68 ], and polyethyleneimine (PEI) [ 69 ] are used to stabilize the MNPs to make mono-dispersed particles in the solution. Also, albumin is used to avoid immunogenicity, achieve tumor accumulation, and cellular uptake of drugs for enhanced therapeutic effect and diagnosis [ 70 ].…”