Biosensing Properties of Zinc Oxide Nanoribbons Toward Creatine: A First-Principles Study

Abstract

In this paper, a nanostructured solid-state biosensor is proposed for the non-enzymatic detection of creatine as a possible stimulus for skeletal/cardiac muscle hypertrophy. Phonon dispersion curve reveals that two-dimensional honeycomb-like ZnO nanostructure applied here has true local minima. Sensing properties of the device toward creatine are theoretically studied by employing first-principles density functional theory associated with non-equilibrium Green&#x2019;s function formalism. For this purpose, a two-probe configuration has been constructed based on ZnO nanoribbon to calculate and assess the adsorption energy, charge transfer, electron transmission probability, current through the sensing device, and its sensitivity taking pristine and creatine-adsorbed ZnO nanoribbon into account. Representation of total and local density of states substantiates strong chemisorption of the carboxyl/imine-ended creatine with the nanoribbon edge/center through n/p-type conduction in conjunction with the adsorption energy of -2.424 eV/-2.292 eV and charge transfer of <inline-formula> <tex-math notation="LaTeX">$0.521 \vert \text{e}\vert $ </tex-math></inline-formula>/-<inline-formula> <tex-math notation="LaTeX">$0.011 \vert \text{e}\vert $ </tex-math></inline-formula>, respectively. The adsorption strength of 1&#x00B0; and 3&#x00B0; amine-ended creatine directed toward the nanoribbon surface is intermediate, with slightly more incline to its center. The current flow is calculated by integrating the transmission probability of electrons in an energy window for both pristine and creatine-adsorbed structures; subsequently, the normalized current difference is featured as the sensing device response with the maximum value of 1184.33&#x0025; under an applied bias of 2 V for the optimal adsorption configuration.