Carbon nanotube (CNT) as a free radical scavenger- A DFT Study

 

Meenakshi Malakar and P.K. Shukla

Department of Physics, Assam University, Silchar-788011, Assam

Email: meenakshimalakar1[at]gmail.com and pkshukla[at]ymail.com

 

Carbon Nanotubes (CNTs), owing to their unique properties, are known to be one of the most interesting materials for applications in various fields including biomedical sciences e.g. development of biosensors, immunosensors, ion channel blockers, bioseparators and biocatalysts. CNTs have also been found to be useful in developing effective delivery systems, e.g. for vaccines, drugs, antigens and genes, and as scaffolds for neuronal and ligamentous tissue growth for regenerative interventions of the central nervous system and orthopaedic sites. It is also reported that CNTs can act as scavengers for free radicals. However, some studies have also reported that CNTs can generate free radicals. Actually, the oxygen free radicals such as OH and OOH radicals are known to cause several neural diseases like Alzheimer disease, Parkinson disease, schizophrenia, etc. Toxicity of free radicals also damages proteins and DNA leading to mutation and cancer. Therefore, it is important to investigate whether CNTs can act as a scavenger for such radicals. Previously, some researchers investigated theoretically the scavenging property of CNTs for some radicals. However, some aspects have not been investigated thoroughly so far. In the present contribution, we have investigated theoretically the scavenging properties of armchair, zigzag and chiral single-walled CNTs toward some oxygen free radicals, using the cluster model of CNTs and density functional theory (DFT) in gas phase and aqueous media. The optimization of stationary points have been done at the M06-2X/3-21G* level of DFT in gas phase and aqueous media and the single-point energy calculations have been carried out at the M06-2X/6-31G** level of theory in both the media. Our results show that the CNTs can act as a potent scavenger for oxygen free radicals.

 

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