Contribution of the Fenton reaction to the degradation of carbon nanotubes by enzymes

The widespread use of carbon nanotubes (CNTs) has raised concerns about the human health and ecological effects CNTs released into environment. Bacteria play an important role in bioremediation waste treatment, their enzymes are mostly responsible for degradation contaminants. However, there still only a few reports bacterial CNTs, evidence showing involvement CNT with mechanisms never been reported. purpose this study is to clarify whether can be degraded by enzymes. In study, oxidized (carboxylated) single-walled (O-SWCNTs) mt2DyP, dye-decolorizing peroxidase Pseudomonas putida mt-2, common soil bacterium, was investigated. After incubation O-SWCNTs recombinant mt2DyP its substrate H 2 O 30 d, optical absorbance Raman spectra revealed O-SWCNTs. inactivation enzyme observed within 60 min start incubation, suggesting that occurred nonenzymatically. accompanied release iron, active center metal, significantly inhibited presence diethylenetriamine pentaacetic acid, chelating agent, indicating were Fenton reaction iron from . same phenomenon P450, which also heme enzyme. Furthermore, we investigated contribution O-SWCNT horseradish (HRP), reported enzymatically rapidly degrade Our results HRP mainly due reaction, negligible enzymatic degradation. This contradicts report but supports subsequent quantitatively very slow transformation HRP. current emphasize received little attention enzymes, must taken consideration will contribute development simple disposal method utilizing bacteria/bacterial