Sporocidic properties of poly(vinyl alcohol)/silver nanoparticles/TEOS thin hybrid films

The sporocidic activity of hybrid materials based on PVA/AgNps/TEOS thin films has been investigated. Deep Agar Method has been applied to study the sporocidic properties of these hybrid materials with different silver concentrations. This method has been used because of the lack of standard methods for testing the sporocidic activity in such materials and due to the specific characteristics of bacterial spore. Clear and pronounced presence of sporocidic activity of the hybrid materials towards spores of control strains Bacillus subtilis ATCC 6633 and Geobacillus stearothermophilus ATCC 7953 has been established. The use of chromatographic paper disks impregnated with PVA/AgNps/TEOS showed the advantages in testing the biological properties of the hybrid material in comparison to the disks obtained by directly cutting the PVA/AgNps/TEOS films. The highest sporocidic activity, although with small deviation of 0.5-1.0 mm, was established at the PVA/AgNps/TEOS hybrid films with concentration of silver precursor 9.2 mg/mL and 18.3 mg/mL. The experiments were performed with the aim to reveal the opportunities for a practical application of the material.