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Updated: Sep 10, 2026
Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering
Published on: June 1, 2016
Transition-metal functionalization of carbon nanotubes enables dual-mode transport and rapid aqueous release of
Bahjat S Hameed1, Faeq A Al-Temimei2, Zainab S Hussain3
1Department of Physics, Faculty of Science, University of Kufa, Najaf, Iraq. Bahjat.sabih@gmail.com.
Context:
Targeted delivery of the chemotherapeutic 2-mercaptopyridine (2-MP) requires robust carriers to mitigate rapid systemic degradation. Because pristine carbon nanotubes (CNTs) exhibit weak drug retention, this study investigates transition-metal-doped (Co, Sc, Ru, V) CNTs as dual-action nanocarriers and electrochemical sensors. While pristine CNTs display weak physisorption with adsorption energy kcal/mol, transition-metal doping induces robust coordinate covalent chemisorption. Ru-doped CNTs exhibit optimal thermodynamic stability with kcal/mol and extended gas-phase drug retention with recovery time s, preventing premature payload leakage. Conversely, in competitive aqueous media, these functionalized carriers facilitate rapid, diffusion-controlled release. Furthermore, 2-MP encapsulation triggers a highly sensitive 34.32% modulation in the HOMO-LUMO energy gap of Co-CNTs in water. These findings establish metal-functionalized CNTs as stable, responsive platforms for targeted 2-MP delivery and real-time electrochemical tracking.
Methods:
Computational investigations were performed using Gaussian 09. Geometry optimizations, vibrational frequency analyses, and single-point energy calculations were executed via density functional theory (DFT) utilizing the M06-2X hybrid meta-GGA functional to account for non-covalent dispersion interactions. A mixed basis set approach was applied with 6-311G(d,p) for non-metal atoms and the LanL2DZ effective core potential for transition metals. Aqueous physiological environments were simulated using the polarizable continuum model (PCM). The physical nature of host-guest interactions was characterized through advanced topological population analyses, specifically utilizing the quantum theory of atoms in molecules (QTAIM), reduced density gradient (RDG), and electron localization function (ELF) embedded in Multiwfn 3.8.
