Cytotoxicity Evaluation of Organophosphorus Flame Retardants using Electrochemical Biosensors and Elucidation of Associated Toxic Mechanisms

In recent years, organophosphorus flame retardants (OPFRs) have been widely used as substitutes for brominated flame retardants with excellent properties, and their initial toxicological effects on the water ecosystem and human health have gradually emerged. However, to date, research on the cytotoxicity and health risks of OPFRs is still limited. Therefore, this study aims to systematically explore the cytotoxic effects and toxic mechanisms of OPFRs on cells. Human liver cancer (HepG2) cells were adopted as an ideal model for toxicity evaluation due to their rapid growth and metabolism. This study proposes a sensitive electrochemical cell-based sensor constructed on a graphitized multi-walled carbon nanotube/ionic liquid/gold nanoparticle-modified electrode. The sensor was used to detect the cytotoxicity of tri(2-butylxyethyl) phosphate (TBEP), tributyl phosphate (TnBP), triphenyl phosphate (TPhP), tri(1,3-dichloro-2-propyl) phosphate (TDCIPP), tri(2-chloropropyl) phosphate (TCPP) and tri(2-chloroethyl) phosphate (TCEP) in the liquid medium, providing insight into their toxicity in water environments. The half-maximal inhibitory concentration (IC