Dual-source mesoporous nanosilicas from horsetail plant and chemical precursors show structural and textural evidence...

This study focuses on the synthesis and characterization of a novel silica material from horsetail-derived bio-silica, modified via mesoporous structure generation (mesoporous bio-silica) and its subsequent application as a carrier for Ascorbic Acid (Vitamin C, VC) delivery. The synthesized material was systematically characterized using low-angle X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), and nitrogen adsorption/desorption isotherms of Brunauer-Emmett-Teller (BET). Raw bio-silica demonstrated an amorphous structure, confirmed by broad XRD peaks. Subsequent templating yielded a mesoporous silica structure exhibiting characteristic MCM-41 diffraction patterns. VC loading significantly altered the textural properties, notably reducing BET surface area and pore volume, which is consistent with pore blocking by VC. FTIR analysis confirmed the successful incorporation of VC through the appearance of characteristic C-H (2850, 2925 cm^-1) and C-C (965 cm^-1) stretching vibrations, while BET/BJH analysis provided quantitative evidence of pore blockage. The VC release from mesoporous silicas showed a slow release profile, reaching a plateau at approximately 13 h. Release efficiency was comparable or adjacent to that of TEOS-based systems in our assays. Compared with TEOS-derived silica, the horsetail-derived silica required fewer synthesis steps and avoided organic solvents, suggesting lower production complexity. These findings indicate that plant-derived bio-silica may serve as an alternative source for silica-based drug carriers.