Plausibility of transition metals (Cr and Mo) doped aluminium nitride nanotubes as electrode materials for GABA sensors: A DFT inquisition

Gamma-aminobutyric acid (GABA) is a key inhibitory neurotransmitter that regulates movement and emotional states, and its disruption causes neurological and psychiatric disorders such as anxiety, epilepsy, Alzheimer’s disease, Parkinson’s disease, autism, and dementia. To diagnose these fatal diseases, this work is designed based on a non-invasive method to detect ultra-low concentrations of various neurotransmitters using nanomaterials, analysing the adsorption mechanism of GABA on pristine and transition metals (TMs) Cr and Mo-doped aluminium nitride nanotubes in the Gaussian 09 platform. The analysed IR spectroscopy data reveal that all complexes form naturally in both pristine and doped nanotubes, as no peak is observed in the imaginary frequency range. In addition, doping Al16N16 nanotubes with Cr and Mo increases the GABA adsorption capacity, and among the different complexes formed during adsorption, Al16N15Mo + GABA shows the strongest adsorption with an energy of –8.89 eV, which is 20% greater than the value for GABA adsorbed in pristine Al16N16 nanotubes. Different thermodynamic properties, such as the analysis of enthalpy, Gibbs free energy, and entropy, confirm the suitability of Mo-doped Al16N16 nanotube for GABA adsorption. Together, Al16N15Mo nanotube shows greater feasibility than pristine and other doped variants as a potential electrode material for GABA sensor development.