Biological and Chemical Co-surfactant for Fabrication of Antibacterial Silver Nanoparticles and Potential Application in Agriculture

Silver nanoparticles (AgNPs) have been widely applied as antimicrobial materials. In this work, a new fabrication method of AgNPs has been proposed through a combination of tea seed saponin extraction as a non-ionic biological surfactant and cetyltrimethylammonium chloride (CTAC) as a co-surfactant. The morphology and optical properties of as-prepared AgNPs were analysed by SEM and UV-vis absorbance measurement, respectively. The results indicate that AgNPs obtained high homogeneous particle sizes with a mean diameter of 44.5 ± 3.8 nm. The optical property of AgNPs was exhibited through a UV-vis absorbance spectrum of ~420 nm. In addition, the antibacterial behaviour of <i>E. coli</i> (ATCC 25922) was increased according to the AgNPs concentration. The diameter of inhibition zones was 12 mm, 14 mm and 16 mm under AgNPs concentrations of 0.8 ppm, 8 ppm and 80 ppm, respectively. Our initial trial treatment of AgNPs in young broccoli (<i>Brassica oleracea</i>) exhibited promising potential for plant protection in agricultural applications.