Simple Ultraviolet–Visible Spectroscopy-Based Assay for Fast Evaluation of Magnetic Nanoparticle Selectivity Changes After Doping

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. Graphical Abstract