Preparation and application of Mn, Si-CQDs in vitamin B6 and in vitro activity analysis

The determination of vitamin B6 (VB6) in food, health products, and pharmaceuticals is of great significance because it plays a crucial role in maintaining health and is a necessary condition for dietary intake. Therefore, the study uses L-Histidine, citric acid, potassium permanganate, and tetraethyl silicate as carbon source and Mn, Si source to prepare Mn, Si-CQDs by a hydrothermal method. The characteristics of the Mn,Si-CQDs are studied by TEM, XPS, FTIR, XRD, and UV-vis spectrum, Mn,Si-CQDs are spherical and well dispersed in aqueous solution, with an average particle size of 5 nm. The effect of different pH and storage time on the fluorescence intensity of Mn, Si-CQDs indicates that Mn, Si-CQDs have good fluorescence stability. The fluorescence of Mn, Si-CQDs can be selectively quenched by VB6 without being affected by interfering other substances, within the range of 0.05-20 μg/mL, The quenching degree ratio of Mn, Si-CQDs , F 0 /F, shows a good linear relationship with the concentration of VB6 (F 0 /F=0.19311+0.03723C (R 2 =0.99882)), with a detection limit of 0.037 μg/mL. The recovery rates were 94.21∼98.80% by the spiked recovery experiments, indicating the high sensitivity and selectivity of the Mn,Si-CQDs . During the antibacterial test, the Mn,Si-CQDs exhibite good antibacterial effects on Staphylococcus aureus, Penicillium, Escherichia coli and Saccharomyces cerevisiae .