Silver-, calcium-, and copper molybdate compounds: Preparation, antibacterial activity, and mechanisms
Sprache des Titels:
Englisch
Original Kurzfassung:
Developing novel compounds with antimicrobial properties can be an effective approach to
decreasing the number of healthcare-associated infections, particularly in the context of medical
devices and touch surfaces. A variety of molybdate powders (Ag2MoO4, CaMoO4, CuMoO4 and
Cu3Mo2O9) were synthesized and characterized, and Escherichia coli was used as a model gramnegative
bacterium to demonstrate their antimicrobial properties. Optical density measurements,
bacterial colony growth, and stained gel images for protein expression clearly showed that silverand
copper molybdates inhibit bacterial growth, whereas CaMoO4 exhibited no bactericidal effect.
All tests were performed in both daylight and darkness to assess the possible contribution of a photocatalytic
effect on the activity observed. The main mechanism responsible for the antibacterial
effect observed for Ag2MoO4 is related to Agþ release in combination with medium acidification,
whereas for compounds containing copper, leaching of Cu2þ ions is proposed. All these effects are
known to cause damage at the cellular level. A photocatalytic contribution to the antibacterial activity
was not clearly observable. Based on the pH and solubility measurements performed for powders
in contact with various media (ultrapure water and bacterial growth medium), silver
molybdate (Ag2MoO4) was identified as the best antibacterial candidate. This compound has great
potential for further use in hybrid powder-polymer/varnish systems for touch surfaces in healthcare
settings.