Neodymium YAG laser chemical vapor deposition growth of luminescent Mo2S3 nanocrystals using bulk MoS2 and its structural, optical properties and caspase-mediated apoptosis in THP-1 monocytic cells

Abstract

Metal-sulphur phase-based semiconductor materials are often investigated in the field of nanotechnology. Herein, we describe the synthetic route to obtain Mo2S3 nanocrystals from MoS2 via a laser-furnace technique. These nanocrystals have been tested for cytotoxicity against the monocytic leukemic THP-1 cell line. The synthetic process caused a phase change from MoS2 to Mo2S3 at a temperature of 1100 °C and a pressure of 400 Torr. Powder X-ray diffraction analysis confirmed the crystallinity and structure and X-ray photoelectron spectroscopy confirmed the chemical composition and oxidation states of the Mo2S3 nanocrystals. The morphology of the Mo2S3 has been observed by using field emission scanning electron microscopy and high-resolution transmission electron microscopy. The in vitro cytotoxicity evaluation of the Mo2S3 nanocrystals was determined in the THP-1 cell line. The cytotoxic potential of the Mo2S3 against THP-1 cells was assessed by the WST-1 assay and intracellular caspase activities. The caspase activities were significantly elevated indicating the initiation of both the intrinsic and extrinsic apoptotic pathways when compared to untreated cells. Field emission scanning electron microscopy revealed that the Mo2S3 NCs compromised the cell membrane integrity resulting in a loss of THP-1 cell viability and apoptosis. Thus, Mo2S3 is an aqueous nanocrystal which shows promising cytotoxicity effect against THP-1 with good photoluminescent properties.