Dopamine detection by doped single-walled carbon nanotube biosensors: A theoretical study

Abstract

In this paper, biosensors of the Fe-Nitrogen-doped zigzag (8, 0) carbon nanotube and Fe-doped zigzag (8, 0) carbon nanotube were offered for detection of dopamine molecule. The adsorption property and sensing mechanism of Fe-doped zigzag (8, 0) carbon nanotube and Fe-N-SWCNT (8, 0) with dopamine were investigated based on density functional theory. The obtained results demonstrated that both Fe-SWCNT and the Fe-N-SWCNT had good adsorption for dopamine, also conductivity also grew when they interacted with it. When dopamine is adsorbed on the surface of the single wall carbon nanotube, a large number of electrons transfer from the Fe-N-doped zigzag (8, 0) single carbon nanotube to dopamine, resulting in lessened frontier orbital energy gap and increased electrical conductivity. On the other hand, when dopamine is adsorbed on the surface of the SWCNT, the electrons transfer from dopamine to the Fe-N-SWCNT, the frontier orbital energy gap rises, while the electrical conductivity declines. Thus, Fe-nitrogen-SWCNT (8, 0) is more suitable and sufficient than Fe-SWCNT (8, 0) for dopamine detection.

Pillared Graphene Structures Supported by Vertically Aligned Carbon Nanotubes as the Potential Recognition Element for DNA Biosensors

“…To reveal the sensing mechanism of the proposed sensor and the conformational changes of the GR aptamer after binding to the ligand molecules GUA, 6GU, 2BP and XAN, we calculated using molecular dynamic simulation. Density functional theory (DFT) calculations showed that adsorption of dopamine on nitrogen-Fe-doped single carbon nanotube (8,0) led to changes to the energy gap [ 34 ]. The simulation results of electrical conductivity changes showed DNA/Cu 2 O-graphene sheet nanostructures can be well used as FET to detect polycyclic aromatic hydrocarbons [ 35 ].…”