Triazine- and Heptazine-Based Carbon Nitrides: Toxicity

Graphitic carbon nitride has attracted extensive interests recently because of its potential in biosensing, photocatalytic, and biomedical applications. Similar to graphene, it is a two-dimensional carbon and nitrogen-based nanomaterial with weak van der Waals forces between each layer. Carbon nitrides can have various structural moieties such as triazine and heptazine. Unlike graphene-substituted nanosheets, the toxicity of graphitic carbon nitrite is largely unknown. In respond to that, toxicological study was carried out to determine its toxicity toward human lung carcinoma epithelial cells (A549). Two formazan-based cell viability assays (water-soluble tetrazolium salt (WST-8) assay and methylthiazolyldiphenyltetrazolium bromide (MTT) assay) were utilized on the A549 cell line to derive the cytotoxicity profile. Both materials demonstrated a dose-dependent toxicological effect with triazine-based carbon nitrides being more cytotoxic than heptazine-based carbon nitrides. These findings are of great importance, and this paves the way for exploring carbon nitride materials in numerous fields such as photocatalysis and electrocatalysis.