In vitro cytotoxicity of covalently protected layered molybdenum disulfide

Layered molybdenum disulfide (MoS₂) is in forefront of materials research. MoS₂ has been reported to display various unique electronic, catalytic and sensing properties. Functionalization of MoS₂ is common as it can improve biocompatibility, electrochemical behaviour, catalytic performance, and sensing abilities. In this study, a cytotoxicity study of MoS₂ functionalized with an organic molecule, thiobarbituric acid (TBA) was conducted. The functionalization of MoS₂ with TBA (MoS₂-TBA) is unique as it was reported to retain metallic 1T-type character which is important for electrochemical applications. In addition, MoS₂-TBA could possibly be utilized to a wider range of applications as it can be further modified due to the presence of alcohol groups. Thus, investigating the toxicity of MoS₂-TBA is essential since it has promising properties for several applications. Functionalized MoS₂-TBA is expected to have different toxicity profile than non-functionalized MoS₂ as several physicochemical properties may have changed after functionalization. The cytotoxicity study has been conducted via two common cell viability assays which are methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and water-soluble tetrazolium salt (WST-8) assay. Human lung carcinoma epithelial cell line (A549) was chosen for this study it is highly probable for nanomaterials to enter the lungs and interact with the body via inhalation through the respiratory tract from the environment. This study has found that MoS₂-TBA has become less toxic as compared to MoS₂.