Synthesis fluorescent magnetic nanoparticles in a microchannel using the La Mer process and the characterization of their properties

This study presents a stable and controllable synthesis of fluorescent magnetic nanoparticles in a flow-through microchannel for the bimodal use of magnetic activated cells sorting and fluorescence-activated cell sorters. The La Mer process is carried out to synthesize magnetic nanoparticles using co-precipitation. Then, the magnetic nanoparticles are coated with conjugation of chitosan and fluorescent isothiocyanate with two different concentrations. The chemical composition of the magnetic nanoparticles is determined by comparing the standard X-ray diffraction peaks of Fe₃O₄, and their sizes are also examined by using field emission scanning electron microscopy and dynamic light scattering measurement. The magnetic property of saturation magnetization and coercive field is characterized in a vibrating sample magnetometer. Also, the possibility of external manipulation in the synthesis of the magnetic particles is demonstrated by separating the synthesized fluorescent magnetic nanoparticles into a non-reacting lamination flow. Finally, their fluorescence property is determined by measuring the fluorescence adsorption spectra and the photoluminescence emission spectra in UV–Vis spectroscopy.