Graphene-like MoS2-modified magnetic C-dot nanoflowers: An efficient magnetic solid-phase extraction adsorbent for monitoring of trace amounts of ibuprofen


Analytical Methods, vol.12, no.12, pp.1570-1578, 2020 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 12 Issue: 12
  • Publication Date: 2020
  • Doi Number: 10.1039/c9ay02752a
  • Title of Journal : Analytical Methods
  • Page Numbers: pp.1570-1578


© 2020 The Royal Society of Chemistry.Graphene-like two-dimensional transition metal dichalcogenides such as MoS2, MoSe2, MoTe2, NbS2, NbSe2, WS2, WSe2, TaS2 and TaSe2 are emerging as promising new-generation materials because of their basic properties complementing those of graphene in practical applications. In this study, graphene-like MoS2-modified magnetic carbon-dot nanoflowers (MoS2@Fe3O4@C-dot NFs) were synthesized via a simple and green hydrothermal synthesis procedure. Carbon dots (C-dots) were obtained from cow's milk by a very simple one-step hydrothermal synthesis method. Owing to the fact that the sandwich layers of MoS2 provide sufficient and effective intermediate layer spaces, a large number of magnetic C-dots can easily enter these spaces between the layers. A MoS2 aqueous solution has good chemical stability and dispersibility in acidic, basic and organic solvents. There is a mutually beneficial relationship between MoS2, C-dots and Fe3O4 particles. Magnetic carbon dots (Fe3O4@C-dots) prevent MoS2 layers from agglomerating, while the chemically very stable MoS2 layers act as a protective layer on magnetic carbon dots. In addition, the -OH and -COOH functional groups of the C-dots lead to improvements in the extraction efficiency of the adsorbent due to the formation of a hydrogen bond between these groups and ibuprofen. Hence, the MoS2@Fe3O4@C-dot NFs as sorbents for the MSPE procedure showed good extraction performance. The new MoS2@Fe3O4@C-dot NFs were used as magnetic solid-phase extraction (MSPE) adsorbents for the separation and enrichment of ibuprofen from pharmaceutical, environmental water and synthetic urine samples before high pressure liquid chromatography (HPLC-DAD) determination. MoS2@Fe3O4@C-dot NFs were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy and SEM-mapping techniques. The optimization of analytically important variables such as pH, adsorbent amount, eluent type and volume, sample volume and extraction time was performed. In the experiments performed, the recoveries of ibuprofen from pharmaceutical, environmental water and synthetic urine samples were in the range of 89-105%. The limit of detection (LOD), limit of quantification (LOQ) and preconcentration factor (PF) were found to be 11 × 10-6 μg mL-1, 34 × 10-6 μg mL-1 and 100, respectively. The relative standard deviation values within the day (intra-day) and between days (inter-day) were calculated to be 1.29% and 3.19%, respectively.