Paramagnetic properties of manganese chelated on glutathione-exfoliated MoS2

Abstract

Generation of zero-dimensional molybdenum disulphide (MoS2) nanoparticles with effective chemical and physical properties have offered a widerange of applications. The advancement in two-dimensional (2D) MoS2 functionalization materials for the fabrication of biomedical applications has become a recent trend owing to their physicochemical properties such as high surface area, mechanical properties, and excellent electrical conductivity. In this study, the pristine bulk MoS2 was exfoliated by probe sonication with glutathione (GSH) as a capping ligand to form MoS2-GSH nanoparticles. Further, the as-prepared MoS2-GSH was coated with amino terminated ethyl polyethylene glycol (MoS2-GSH-AEPEG) through electrostatic interactions between GSH and AEPEG. Thereafter, both MoS2-GSH and MoS2-GSH-AEPEG nanoparticles (NPs) were chelated with manganese (Mn) metal ion to form magnetic MoS2-GSH-Mn and MoS2-GSH-AEPEG-Mn NPs. The obtained MoS2-GSH-Mn and MoS2-GSH-AEPEG-Mn nanoparticles exhibited a spherical in shape with sizes of 60.7 and 80.6 nm, respectively. The chelated Mn2+ in the prepared MoS2 NPs was confirmed by XPS and Raman spectroscopy. The paramagnetic properties of the MoS2-GSH-Mn and MoS2-GSH-AEPEG-Mn samples were investigated using a superconducting quantum interference device at 5 K temperature and the saturation magnetization was calculated to be 17.5 and 15 emu/g for MoS2-GSH-Mn and MoS2-GSH-AEPEG-Mn, respectively. The MoS2-GSH-Mn exhibited higher magnetic hysteresis loops than MoS2-GSH-AEPEG-Mn due to shielding effects of nonmagnetic nature of PEG coating.