First-Principles Insights into the Acetic Acid Sensing Capability of the C₃₉N Armchair Nanotube

Abstract

In this paper, (5,5) single-walled carbon nanotube was doped by substitutional nitrogen (N) atom forming bridgehead C-N bonds in the resulting C39N armchair nanotube. It was then interacted with acetic acid to investigate its detection capability using first-principles calculations in the context of Density Functional Theory (DFT). As known, DFT is a very efficient and accurate method in calculating the properties of the atoms and molecules, and their interactions. Accordingly, the O-H bond of the acid has not undergone a heterolytic dissociation caused by the weak interaction of the materials. In the valence region of the C39N-acid, the O atoms (2p) are the main causes of additional states as shown in the projected density of states (pDOS). Calculations of the charge density difference revealed the occurrence of charge redistribution and nonuniform charge transfer between the acid and the sidewalls of the C39N. Further topological investigation of the system revealed no localized electrons between the interaction points indicating a physical binding mechanism. These electronic responses have shown the biosensing ability of C39N to detect and capture acetic acid.