Simple Ultraviolet-Visible Spectroscopy-Based Assay for Fast Evaluation of Magnetic Nanoparticle Selectivity Changes...

Simple ultraviolet-visible spectroscopy-based methodology was proposed and utilized for the initial characterization of potential changes in selectivity of doped magnetic nanoparticles. Doped and undoped iron(II,III) (Fe₃O₄) magnetic nanoparticles were synthesized by the coprecipitation method. The doping processes of nanoparticles were confirmed using optical emission spectrometry, while the sizes of undoped and Cu-doped nanoparticles were investigated using a high-resolution field emission scanning electron microscope. The average diameters of nanoparticles were 8.34±1.78 nm and 9.12±1.93 nm, for doped and undoped materials, respectively. The influence of the nanoparticle's doping on their selectivity towards chosen analyte was monitored by the spectral techniques such as ultraviolet-visible and optical emission spectrometry. The interaction between Cu-doped Fe₃O₄ nanoparticles and cuprizone (a compound forming the characteristic colorful complex with copper) was confirmed. The elaborated studies proved the potential of ultraviolet-visible spectroscopy for the fast qualification of magnetic nanoparticles in terms of their ability to separate the selected analyte from the sample matrix.