Toxicity study of CaCe₂S₄

Abstract

In recent years, rare earth sulfides have received attention for their interesting thermoelectric and optical properties.1 They exhibit a fairly wide range of colors, which makes them promising candidates as pigments.2 The demand for red colored pigments in industrial application is high but the current ones in use are not environmentally friendly. This has garnered attention towards the rare-earth sulfides. Among the rare-earth sulfide compounds, Ce₂S₃ is a highperformance pigment of red color. It is particularly interesting as doping with alkaline earth metal stabilizes the structure of Ce₂S₃ at low temperature and plays a role in tuning its color from red to orange. This thesis presents the cytotoxicity study of an alkaline earth doped rare earth sulfide of red color, CaCe₂S₄. Cytotoxicity of CaCe₂S₄ and CdS was evaluated on human dermal fibroblasts cells (HDFα) with Lactase dehydrogenase (LDH) assay. The study showed higher toxicity of CaCe₂S₄ compound at 1000 μg/mL-50 μg/mL. At concentrations of 1 ng/mL-200 ng/mL CaCe₂S₄ showed considerably low toxicity compared to commercially successful red pigment CdS, which makes it a reliable environment friendly pigment.