Acute toxicity of carbon-based nanomaterials to Escherichia coli is partially dependent on the presence of process impurities

Abstract

Using inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectroscopy, we perform a compositional analysis of ten commercially available and laboratory carbon nanomaterials (CNMs). It is found that, depending on the type of CNMs and applied purification technology, they can contain 20 to 50 out of the 62 identified chemical elements, totally amounting to 0.03 to 23.1% of the weight of the sample under analysis. It is shown that the acute toxicity of CNMs, which is determined according to the effect on the luminescence intensity of a sensor Escherichia coli strain carrying cloned luxCDABE genes of Photobacterium leiognathi, is partially dependent on the presence of process impurities of Ni, Y, Zn, Sm, Gd, Ho, and Fe. With an increase in the time of contact between the sensor microorganism and the CNM, the latter develop intrinsic biotoxicity, which decreases the significance of the impurity composition in determining this activity within the dynamics of the experiment.