DFT-Based Electronic and Xanes Spectra of Pd@Au12 and Au13 Nanoclusters for Antibiotic Sensing Applications

Abstract

The development of effective and efficient sensors is crucial in facing the challenge of antibiotic resistance. Gold and palladium nanoclusters show enormous potential in antibiotic sensor applications. This study aimed to analyze the electronic properties, specifically the Density of States (DOS) and Partial Density of States (PDOS), and the optical properties, such as X-ray Absorption Near Edge Structure (XANES), of Pd@Au12 and Au13 as materials for antibiotic sensors. Calculations were performed using Density Functional Theory (DFT) with the GGA-PBE functional approach and the PAW scalar relativistic method for the interaction between valence electrons and the atomic core. The optimization results of the Pd@Au12 and Au13 structures maintained a stable icosahedral structure with a size of 0.468 nm. The Density of States analysis consistently showed metallic characteristics for both Pd@Au12 and Au13, with the Fermi energy of Pd@Au12 at -4.738 eV, slightly higher than that of Au13 at -5.2663 eV, indicating increased reactivity. The Partial Density of States revealed the hybridization of the Pd 4d orbital with the Au 5d orbital. The Pd K-edge XANES spectra indicated the availability of unoccupied 4p orbitals in the Pd atom, confirming its central role in reactivity. All these properties indicated a strong potential for these materials as sensors. This study laid a solid foundation for understanding nanocluster interactions in the future development of antibiotic sensors.