Biodegradation of Carbon Nanotubes, Graphene, and Their Derivatives

Abstract

Carbon nanotubes (CNTs), graphene (GRA), and their derivatives are promising materials for a wide range of applications such as pollutant removal, enzyme immobilization, bioimaging, biosensors, and drug delivery and are rapidly increasing in use and increasingly mass produced. The biodegradation of carbon nanomaterials by microbes and enzymes is now of great importance for both reducing their toxicity to living organisms and removing them from the environment. Here we review recent progress in the biodegradation field from the point of view of the primary microbes and enzymes that can degrade these nanomaterials, along with experimental and molecular simulation methods for the exploration of nanomaterial degradation. Further efforts should primarily aim toward expanding the repertoire of microbes and enzymes and exploring optimal conditions for the degradation of nanomaterials. Multiple types of microbes including bacteria and fungi have the ability to degrade carbon nanotubes (CNTs), graphene (GRA), and their derivatives and in the future more species with this ability will be found. Current applications of numerous enzymes in the biodegradation of CNTs, GRA, and their derivatives provide crucial clues for the design and development of safe nanomaterials and are helpful in understanding their fates in the environment. A variety of experimental and molecular simulation technologies have been used to jointly explore the biodegradation of CNTs, GRA, and their derivatives. Biodegradation approaches for CNTs, GRA, and their derivatives are moving from theory to plausible remediation practice for the removal of these materials from the environment but still face many challenges.