Two New Inner-sphere Pt(II) Thiosemicarbazone Schiff Base Complexes Immobilized into Magnetic Nanoparticles: Synthesis, Characterization, and Biological Investigations

Two inner-sphere Pt(II) complexes were synthesized and characterized using various tools, one of which is [Pt(HL2)(H2O)2]Cl. When immobilized into to the surface functionalized magnetite, it formed Pt(L2)/MNPs, a multifunctional material suitable for various applications. Among the tested compounds, it exhibited the strongest anticancer and antimicrobial properties that were comparable to the standards. It demonstrated antioxidant activities which were close to the ascorbic acid standard. Additionally, it demonstrated antioxidant activities close to the ascorbic acid standard and had the lowest optical band gaps, indicating its possible use in solar cells and related applications. [Display omitted] •Synthesis of two inner-sphere Platinum(II) complexes.•DFT calculations conducted on ligands and their complexes.•Binding affinity investigation of compounds with Bovine Serum Albumin (BSA).•DNA cleavage studies performed on ligands and Pt(II) complexes.•Immobilization of complexes onto the surface of magnetic nanoparticles (MNPs).•Evaluation of anticancer, antibacterial, and antioxidant activities of all compounds.•Calculation of optical band gap energy for all compounds. This study explores the synthesis, characterization, and biological investigations of two new Pt(II) thiosemicarbazone complexes immobilized in magnetic nanoparticles (MNPs). MNPs exhibit distinctive physical and chemical properties that enhance their interactions with biological targets. These traits make them particularly useful, especially when combined with drugs, increasing therapeutic effectiveness while also serving as efficient diagnostic tools in imaging techniques. The two Pt(II) complexes are represented by the formulas [Pt(HL1)(H2O)]Cl and [Pt(HL2)(H2O)2]Cl. The ligand, H2L1 signifies (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazine-1-carbothioamide, while H2L2 stands for (Z)-N-ethyl-2-(2-oxoindolin-3-ylidene)hydrazine-1-carbothioamide. The ligands and their Pt(II) complexes were characterized through various techniques, including elemental analysis, mass spectrometry, thermal analysis, powder X-ray diffraction (XRD), FT-IR, NMR, and UV–visible spectroscopy. The two complexes form a square planar geometry, in which H2L1 performs as a mononegative tridentate while H2L2 acts as a mononegative bidentate. Density Functional Theory (DFT) calculations were utilized to investigate the molecular configurations of the ligands and its Pt(II) complexes. The UV–visible and fluorescence spectro