Cytotoxicity of layered metal phosphorus chalcogenides (MPX_Y) nanoflakes; FePS₃, CoPS₃, NiPS₃

Metal phosphorus chalcogenides is a new class of 2D materials that have shown interesting semiconducting, electronic, anisotropic, magnetic, dielectric, structural and optical properties. Recently, NiPS₃, FePS₃ and CoPS₃ in particular have been highlighted for promising potential in important energy applications such as electrocatalysts for water splitting and hydrogen storage. However, little is known about the toxicological hazards that they may pose on humans. Here, we investigated the cytotoxicity of NiPS₃, FePS₃ and CoPS₃ on human lung carcinoma cells (A549) and normal human bronchial cells (BEAS-2B) to address this concern. Upon treatment of these cells with different MPX_Y materials, we determined the remaining cell viability using water soluble tetrazolium salt (WST-8) assay. We found that CoPS₃ was most toxic followed by FePS₃ with intermediate toxicity while NiPS₃ showed the lowest toxicity among the three materials tested for both cell lines. When viewed with other layered materials, these MPX_Y samples present comparable toxicities with transition metal dichalcogenides and black phosphorus at low concentrations.