Vol. 13 | No. 3 |1478-1485| July - September | 2020 ISSN: 0974-1496 | e-ISSN: 0976-0083 | CODEN: RJCABP http://www.rasayanjournal.com http://www.rasayanjournal.co.in Rasayan J. Chem., 13(3), 1478-1485(2020) http://dx.doi.org/10.31788/ RJC.2020.1335760 Bio-Friendly Synthesis of Silver Nanoparticles Using Mangrove Rhizophora stylosa Leaf Aqueous Extract and Its Antibacterial and Antioxidant Activity Nancy Willian 1,2 , Syukri 1 , Zulhadjri 1 , Arniati Labanni 1 , Syukri Arief 1 * 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Andalas, Kampus Limau Manis, Padang 25163, West Sumatera-Indonesia 2 Department of Chemistry Education, Faculty of Teaching and Education, Raja Ali Haji Maritime University, Tanjungpinang, Riau Archipilago-Indonesia *E-mail : syukriarief@sci.unand.ac.id _____________________________________________________________________________________ ABSTRACT Plant mediated biosynthesis of nanoparticles is going important due to simple processes and non-toxic materials utilization. Rhizophora stylosa (RS) mangrove leaf extract was successfully used as a bioreductor in the production of AgNPs by varying the concentration of silver nitrate and the amount of extract. Leaf extract is made by dissolving 10 grams of dried leaf powder in 100 ml double-distilled water (DDW). The concentration of silver nitrate was variable by 1,5, 10 mM with different amounts of leaf extract. The UV-Vis absorption spectrum of colloid in the range between 439-453 nm confirmed that AgNPs have been successfully synthesized. FT-IR absorption band shows the feasible biomolecules of Rhizophora stylosa responsible for the production of silver nanoparticles were amine, alcohol, phenol, alkyl halide, and aromatic combinations groups. The XRD pattern regulates that the synthesized AgNPs were in a face-centered cubic (fcc) crystal structure with an average size of 25 nm. TEM images informed that the synthesized AgNPs have a spherical shape with a size range between 9 to 57 nm. The average size of the nanoparticles was 30 nm. The solution of stable silver nanoparticle colloid from 1 until 3-month incubation. AgNPs have good antibacterial and antioxidant activity compared to pure plant extract. Keywords: Green Synthesis, Silver Nanoparticles, Rhizophora stylosa, Antibacterial, Antioxidant © RASĀYAN. All rights reserved INTRODUCTION Nanotechnology is one of the essential parts in the synthesis of nanoparticles (NP) with dimensions of 1- 100 nm. The atoms of nanoparticles are more concentrated on the surface than those of microparticles, which increases their functional ability 1 . They have excellent properties such as large surface area, structural properties, and long shelf life. Nanomaterial properties have the potential for disease diagnosis. Plant mediated synthesis called biosynthesis provides a more effective technique than physical and chemical methods. The main advantages of biosynthesis are not using toxic chemicals, temperature, energy, and high pressure during nanoparticle synthesis 2 . Biological methods as a safe, clean, and environmentally friendly synthesis can be established for large-scale production 3 . Silver nanoparticles exhibit very high potential in biological applications, especially as an antibacterial and antioxidant agent. Mangrove plants, as traditional medicinal plants, have been widely used by coastal communities 4 . Rhizophora genus has been used traditionally as a source of dyes and medicines, especially bark 5 . It also has been investigated as antibacterial and antioxidant activity due to the content of flavonol derivatives, mainly catechin, and epicatechin. This mangrove Rhizophora stylosa can be found along the coast of Riau Archipelago, Indonesia. Leaf extracts of mangrove plants act as capping and reducing agents as well, which are responsible for crystal growth, hence determine the nature of silver nanoparticles 6 . There are very few mangrove species investigated for antimicrobial and antioxidant compounds and need to be explored further 7 . It is recommended to use a renewable source of mangrove plants from natural products combined with AgNPs as an antibacterial and antioxidant agent. In this study, the secondary metabolic