p-ISSN 1693-5683; e-ISSN 2527-7146 34 Vol. 19, No. 1, May 2022, pp. 34-40 Research Article Synthesis of Silver Nanoparticles Using Premna serratifolia Linn. Leaf Extract as Reducing Agent and Their Antibacterial Activity Chris Octavianus 1 , Imelda Hotmarisi Silalahi 2 , Gusrizal Gusrizal 2* 1 Master Program of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Tanjungpura, Jl. Prof. Dr. H. Hadari Nawawi, Pontianak 78124, Indonesia 2 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Tanjungpura, Jl. Prof. Dr. H. Hadari Nawawi, Pontianak 78124, Indonesia https://doi.org/10.24071/jpsc.003185 J. Pharm. Sci. Community, 2022, 19(1), 34-40 Article Info ABSTRACT Received: 08-03-2021 Revised: 10-10-2021 Accepted: 18-10-2021 *Corresponding author: Gusrizal Gusrizal email: gusrizal@chemistry.untan.ac.id Keywords: Antibacterial; Premna serratifolia Linn; silver nanoparticles; Premna serratifolia Linn. leaf extract has been used as a reducing agent in the synthesis of silver nanoparticles (AgNPs). Various synthesis parameters such as reaction time, concentration and the pH of the Premna serratifolia Linn. leaf extract, and silver nitrate concentration were investigated. In addition, the stability of synthesized AgNPs and their activity against Staphylococcus aureus and Escherichia coli have also been investigated. The results of the experiment showed that Premna serratifolia Linn. leaf extract reduced silver ions resulting in AgNPs. In addition, the AgNPs colloid showed a gradual change in color from transparent green to yellow. At the same time, its ultraviolet (UV)-Visible spectra exhibited the typical surface plasmon resonance peak at around 400-415 nm. The optimum reaction conditions in the formation of AgNPs are 40 minutes of reaction time using silver nitrate 1.5x10 -4 M and Premna serratifolia Linn leaf extract 80 ppm at pH 10. The particle size of synthesized AgNPs distributes from 48.3-157 nm with an average size of 58.7±14.4 nm and is stable at least for 1- month storage under ambient conditions. The antibacterial test shows that synthesized AgNPs are effective against both Escherichia coli and Staphylococcus aureus. INTRODUCTION With the emergence of biofilm community bacterial infections and their resistance, the medical world needs a new antibacterial class. In this era, the use of alternative antibacterial agents such as silver finds momentum. Silver nanoparticles (AgNPs) research provides good knowledge about its efficacy against bacterial infections. As an antibacterial agent, AgNPs have attracted more attention from epidemiology researchers. Many publications have reported the studies of the antibacterial activity of AgNPs (Das et al., 2020). The chemical reduction process can be used to produce AgNPs. As the precursor, silver ions are reduced by a reducing agent and then stabilized by a capping agent. In some cases, a reducing agent plays a role as a capping agent simultaneously (Gusrizal et al., 2018). The limitation of the chemical reduction process is that the reducing agents are not environmentally friendly. On the other hand, green synthesis using plant material extracts plays a role in minimizing the toxic waste or byproducts. Green synthesis using plant extracts is eco-friendly, rapid, low in cost, and produces nontoxic waste, and provides protection to human health (Ahmad et al., 2019; Srikar et al., 2016). The use of plant material extract in the synthesis of AgNPs has been recently reported (Ahmad et al., 2019; Chandra et al., 2020; Das et al., 2020). The extracts of leaves, roots, stems, bark, flowers, and fruit act as a reducing and capping agent. Phenolic and flavonoid content in the plant material extract can be utilized for reducing silver ions and stabilizing the synthesized AgNPs (Jadhav et al., 2018).