Mass Spectrometric Investigation of Organo-Functionalized Magnetic Nanoparticles Binding Properties toward Chalcones

Chalcones are naturally occurring compounds exhibiting multiple biological functions related to their structure. The investigation of complexes formed by chalcones, namely 2',4'-dihydroxy-2-methoxychalcone (DH-2-MC) and 2',4'-dihydroxy-3-methoxychalcone (DH-3-MC), with organo-functionalized Fe₃O₄ magnetic nanoparticles using mass spectrometric techniques is reported. The magnetic nanoparticles were obtained by the silanization of Fe₃O₄ particles with 3-aminopropyltrimethosysilane, which were subsequently reacted with 3-hydroxybenzaldehyde (3-HBA) or 2-pyridinecarboxaldehyde (2-PCA), resulting in the formation of Schiff base derivatives. The formation of their complexes with chalcones was studied using electrospray (ESI) and flowing atmosphere-pressure afterglow (FAPA) mass spectrometric (MS) ionization techniques. The functional nanoparticles which were synthesized using 3-hydroxybenzaldehyde displayed higher affinity towards examined chalcones than their counterparts obtained using 2-pyridinecarboxaldehyde, which has been proved by both ESI and FAPA techniques. For the examined chalcones, two calibration curves were obtained using the ESI-MS method, which allowed for the quantitative analysis of the performed adsorption processes. The presence of Cu(II) ions in the system significantly hindered the formation of material-chalcone complexes, which was proved by the ESI and FAPA techniques. These results indicate that both mass spectrometric techniques used in our study possess a large potential for the investigation of the binding properties of various functional nanoparticles.