ORIENTAL JOURNAL OF CHEMISTRY www.orientjchem.org An International Open Access, Peer Reviewed Research Journal ISSN: 0970-020 X CODEN: OJCHEG 2020, Vol. 36, No.(6): Pg. 1103-1106 This is an Open Access article licensed under a Creative Commons license: Attribution 4.0 International (CC- BY). Published by Oriental Scientific Publishing Company © 2018 Effect of pH on Size and Concentration of Silver Nanoparticles Synthesized using Ixora coccinea Linn. Leaf Extracts DARWIN F. REYES 1 *, GIL FABIEN S. CABRERA 2 , SHEMMA MICA V. MATA 2 , JAZMIN PARIZ D. SAN PEDRO 2 , JADD CHRISTIAN C. PALIOC 2 and GERVIN S. TANDINGAN 2 1 Chemistry and Environmental Science Department, College of Arts and Sciences, Nueva Ecija University of Science and Technology, General Tinio St., Cabanatuan City, Nueva Ecija 3100 Philippines. 2 Laboratory High School, Nueva Ecija University of Science and Technology, General Tinio St, Cabanatuan City, Nueva Ecija 3100 Philippines. *Corresponding author E-mail: darwin.chem@gmail.com http://dx.doi.org/10.13005/ojc/360612 (Received: October 11, 2020; Accepted: November 12, 2020) ABSTRACT The synthesis of silver nanoparticles via plant-mediated approach is an emerging area of research interest worldwide. The procedure is cost-effective and does not require the use of toxic chemicals and complicated reaction conditions. In the present investigation, silver nanoparticles were prepared using the leaf extracts of Ixora coccinea Linn., a common ornamental shrub in the Philippines, as the reducing agent. The effect of pH on the synthesis was investigated, and results showed that the quality of the synthesized silver nanoparticles changes in varying pH of the reducing agent. Keywords: Green synthesis, Ixora coccinea Linn., pH, plant-mediated synthesis, Silver nanoparticles. INTRODUCTION Nanotechnology is a promising field nowadays due to its multiple applications in various industries 1 . Nanoparticles having the range of 1-100 nm have interesting properties as compare to their bulk counterpart. In particular, silver nanoparticles (AgNPs) have been receiving fascination from people since the Middle Ages due to its unique properties and applications 2 . AgNPs have distinct physical and chemical properties that make them of potential value in microelectronics and medical imaging industries to name a few 3 . Different methods of AgNP synthesis have been developed. One of the methods is the biological synthesis that emerged as green alternatives because it is cost-effective and environment-friendly 4 . The biological synthesis involved the use of environmentally benign materials as reducing agents such as disaccharide 5 , plant extracts 6-8 , fungus 9 and bacteria 10 . Of the green methods the application of plant extracts emerged due to reasons that it eliminates the elaborate process of maintaining cell cultures and aseptic environments 4 . Brief communication