Enhanced selective extraction of biogenic amines using carboxyl-functionalized SBA-15 and SBA-16 mesoporous silica

This study investigates the adsorption behavior of biogenic amines (BAs) using mesoporous silica materials, specifically SBA-15 and SBA-16, as well as their carboxyl-functionalized derivatives (SBA-15-C and SBA-16-C). The materials were synthesized and characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, and nitrogen adsorption-desorption analyses, confirming successful functionalization and the preservation of mesoporous structures. Adsorption kinetics and isotherms were evaluated to assess the efficiency and capacity of these materials in adsorbing phenylethylamine and tryptamine. The results demonstrated that carboxylation, despite reducing pore size and surface area, significantly enhanced the adsorption capacity. SBA-15-C exhibited the highest adsorption capacity, with a maximum of 129.9 mg g⁻¹, surpassing other recently reported adsorbents. The primary adsorption mechanisms were identified as hydrogen bonding and N-H bond interactions between the -NH₂ groups of BAs and the -OH or -COOH groups on the SBA surfaces. Additional mechanisms, including ion-dipole interactions and size exclusion effects, also contributed to the adsorption process. The improved performance of carboxylated SBA materials is attributed to their increased negative surface charge, which enhances their affinity for positively charged BAs. Additionally, density functional theory calculations and molecular docking simulations were employed to further investigate the interaction mechanisms between the adsorbents and BAs, confirming the significance of electrostatic interactions and hydrogen bonding at specific binding sites. These findings suggest that carboxylated SBA-15 is highly effective for the selective extraction of BAs from complex matrices, offering potential for practical applications in food safety.