A comparative DFT study on the interaction of Selegiline drug with Carbon nanotube and Carbon Nanocage

Introduction: Selegiline, also known as L-deprenyl, is a substituted phenethylamine. At normal clinical doses, it is a selective irreversible MAO-B inhibitor. In larger doses itloses its specificity and also inhibits MAO-A. It is available in pill form under many brand names and is used to reduce symptoms in early-stage Parkinson's disease. Atransdermal patch (brand name, Emsam) is used to treat depression. Selegiline, also known as L-deprenyl, is a substituted phenethylamine. At normal clinical doses, it is aselective irreversible MAO-B inhibitor. In larger doses it loses its specificity and also inhibits MAO-A. It is available in pill form under many brand names and is used toreduce symptoms in early-stage Parkinson's disease. A transdermal patch (brand name, Emsam) is used to treat depression. In this research, to expand the domain of zigzag (۶,۰) nanotube (CNT) and Nano cage C۳۰ for selegiline delivery application, we investigated the interaction of Selegiline functionalized CNT by using density functional theory (DFT) calculations. Method: All calculations of this work are performed by using the M۰۶–۲X, DFT method and the ۶-۳۱G(d) level of theory as implemented in a locally modified version of the GAMESS program[۲۶]. The models of study include individual Selegiline and CNT,Cage molecules and combinations of each of drug and nanotube. Optimized geometries and energies are evaluated for all models at the mentioned theoretical level(see Table ۱). Eq. ۱ is used to evaluate the adsorption energies (Eads): Eads= E(Drug+nanomaterials)– E(Drug)– E(nanomaterials). Results & Conclusions: The M۰۶۲X functional predicts that the order of magnitude of electrical conductivity of Carbon nanostructures is as follows tube>cage. The Selegiline drug prefers to be adsorbed on the Carbon nanostructures with adsorption energy about - ۰.۲۵۰ and -۰.۱۷۸ eV for cage and tube respectively. Based on the density of states analysis, it was demonstrated that the electrical conductivity of the Carbon nanostructures is decreased by the drug adsorption, indicating that they can be used in the Selegiline sensors. The order of magnitude of the sensitivity is as follows: SCage>>STube This trend corresponds to the decrease of the structural curvature in the Carbon nanostructures. Finally, a short recovery time of about ۰.۵۴s and ۴.۴ns is predicted for cage and tube respectively, at ۲۹۸K.