Abstract:
Magnesium-based hydrotalcite (MAL), aspartic acid (ASP)-loaded hydrotalcite (MALA) and ASP and Ag
+ co-loaded hydrotalcite (MALAA) were prepared using the nucleation crystallisation method, and their structures and morphologies were characterised by means of X-ray diffraction and transmission electron microscopy, and both ASP and Ag
+ were successfully loaded onto MAL with morphological changes. The effect of concentration on the growth inhibition of Staphylococcus aureus (
S. aureus) by different materials was tested by colony counting method, and the results showed that the inhibition rate of MAL on
S. aureus was only 5.8% when the concentration was 4 mg·mL
-1, while the inhibition rate of MALAA reached 99.7%. The bacterial inhibition mechanism of the modified magnesium-based hydrotalcite was analysed by inductively coupled plasma and UV-visible spectrophotometer techniques. The modified Mg-based hydrotalcite MALA was adsorbed on the negatively charged
S. aureus by changing its morphology, increasing its contact area with bacteria and using electrostatic effect, and the introduction of Ag
+ further increased the potential difference between the two, which facilitated the rupture of the cell membrane of
S. aureus and decreased the integrity of the bacterial cell membrane, resulting in a significant increase in the content of extracellular metal ions (K
+, Ca
2+, and Mg
2+) and protein content, and a significant increase in the content of MALA, and a significant increase in the content of MALA. content were significantly increased, and MALAA had a better bacterial inhibition effect. This kind of material is expected to be used in food, cosmetics and other packaging fields that require high microbiological safety.