Photoinduced toxicity mechanisms of AgNPs to microalgae Chlorella pyrenoidosa in the presence of hematite nanoparticles: insights from transcriptomics, metabolomics and the photochemical index

The environmental risk induced by a low concentration of AgNPs is small, but naturally occurring minerals in the environment may increase the environmental risk of AgNPs. AgNPs attachment to HemNPs have caused photoinduced cytotoxicity, elevating the AgNPs toxicity to C. pyrenoidosa by producing free radicals and improving photocatalytic activity under illumination. It is likely that other iron mineral particles, such as goethite and ferrihydrite, may also increase the toxicity of AgNPs. Currently, studies on the photochemical properties and subsequent ecological effects of ENP mixtures are lacking. Our findings are expected to help provide more realistic assessments of the environmental risks of ENPs and new insights for the joint environmental risk assessment of ENPs and natural iron minerals.