Cytotoxicity assessment of nanoplastics and associated additives using an electrochemical sensor based on carbon nanohorn/gold nanoparticles

Nanoplastics (NPs) has received considerable attention as a growing global environmental concern. One of the primary concerns associated with NPs is the potential release of harmful additives through leaching, which can pose a risk to human health. However, the combined effects of NPs and their additives on human cells remain unclear. Therefore, it is crucial to evaluate the single and combined effects of NPs and their additives promptly and accurately. Herein, a sensor was developed based on the carbon nanohorn/gold nanoparticles, which can be used to identify the electrochemical signals of human hepatocellular carcinoma (HepG2) cells sensitively. The single and combined toxicities of polystyrene NPs (PS-NPs) and two commonly used additives (bisphenol A and lead) were detected. The median inhibition concentration (IC50) of PS-NPs, bisphenol A, and lead on HepG2 cells were 398.05 μg/mL, 79.25 μM, and 106.27 μM, respectively. The combined cytotoxicity of PS-NPs and the associated additives exhibited an additive effect. Furthermore, the toxic effect mechanisms were discussed from cytotoxicity, oxidative stress and cellular apoptosis perspectives. This research introduces a highly sensitive tool for determining the cytotoxicity of nanoplastics and their associated additives, which also offers valuable insights into the underlying mechanisms of their cytotoxic effects.