A new selenium nanomaterial: structural insights, nonlinear optical properties (DFT study), and biological potential

Abstract

Context: This study investigates the synthesis, structural characteristics, thermal properties, and biological activity of the double selenate salt Na₂Cd(SeO₄)₂·2H₂O. The synthesis of this compound was driven by the need for novel materials with potential applications in medicinal chemistry and materials science. The structural integrity and physicochemical properties of Na₂Cd(SeO₄)₂·2H₂O were confirmed through a series of characterization techniques, including FT-IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic light scattering (DLS), and zeta potential measurements. The thermal behavior of the compound, exhibiting a multi-stage decomposition pattern, provides important insights into its stability and transformation mechanisms, essential for its potential use in various applications. Biological testing, conducted on the HepG2 liver cancer cell line, revealed a dose-dependent cytotoxic effect, with morphological changes and cytoskeletal disruption at higher concentrations, highlighting the compound's anticancer potential. The compound also demonstrated a high zeta potential, indicating good colloidal stability and suggesting favorable bioavailability. These findings underscore the relevance of Na₂Cd(SeO₄)₂·2H₂O for biomedical applications, particularly in anticancer therapies, where its unique combination of properties may offer therapeutic advantages.

Methods: Quantum chemical calculations were performed using density functional theory (DFT) to gain insights into the electronic structure, molecular geometry, and nonlinear optical (NLO) properties of Na₂Cd(SeO₄)₂·2H₂O. Molecular electrostatic potential (MEP) mapping revealed nucleophilic and electrophilic activity regions, pointing to possible reactive sites. Frontier molecular orbital (FMO) analysis indicated a moderate HOMO-LUMO energy gap, suggesting a balance between stability and reactivity. Thermal decomposition stages were characterized using TGA and DSC, with identifiable mass loss steps corresponding to water release and selenium dioxide formation. In vitro biological evaluation was conducted on HepG2 cells using MTT assays, immunofluorescence staining, and morphological analysis. The IC₅₀ value was established at approximately 0.05 µg/ml. Zeta potential and DLS analyses were employed to assess colloidal behavior and particle distribution. Together, these methodologies support the promising physicochemical and biological profile of Na₂Cd(SeO₄)₂·2H₂O, justifying its further investigation for nanomedicine and drug delivery applications.

Keywords: Cytotoxicity; DFT calculations; NLO; Na2Cd(SeO4)2·2H2O; Thermal analysis.