Vol.:(0123456789) 1 3 Journal of Inorganic and Organometallic Polymers and Materials https://doi.org/10.1007/s10904-020-01497-7 Formation of Silver Nanoparticles via Aspilia pluriseta Extracts Their Antimicrobial and Catalytic Activity A. O. Nyabola 1  · P. G. Kareru 1  · E. S. Madivoli 1  · S. I. Wanakai 1  · Ernest Gachui Maina 1 Received: 18 January 2020 / Accepted: 7 March 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Green synthesized metallic nanoparticles are continually receiving attention as antimicrobial agents and catalyst for degra- dation of a host of organic compounds. In this study, silver nanoparticles were synthesized using Aspilia pluriseta extracts and evaluated for their antimicrobial and photocatalytic activity. Using a UV–Vis spectrophotometer, the surface plasmon resonance observed at 427 nm indicated the materialization of silver nanoparticles. Probable vibrational stretches that are characteristic of silver nanoparticles such as –OH stretching vibrations and –CH 2 vibrational stretch, were identifed using an FT-IR spectrophotometer. In order to understand the morphology and composition of the synthesized nanoparticles, they were studied further using scanning electron microscope (SEM), dynamic light scattering analyzer (DLS), transmission elec- tron microscope (TEM) and X-ray difractometer (XRD) hence revealing formation of crystalline, spherically shaped silver nanoparticles. The synthesized silver nanoparticles (AgNPs), exhibited broad-spectrum activity which was concentration dependent against; two-gram positive bacteria (Bacillus subtilis and Staphylococcus aureus), two-gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and the fungal (Candida albicans). Efectiveness of the nanomaterials in photocatalytic degradation was based on irradiation time. Decolorization and degradation of the dye took less than 30 min. Keywords Aspilia pluriseta extracts · Silver nanoparticles · Antimicrobial · Catalytic activity 1 Introduction In addition to energy crisis and depletion of ozone layer resulting to global warming, challenges related to rapid growth of towns and industrialization such as waste con- trol, degradation of organic components and wastewater treatment needs to be addressed [1]. A lot of efort is being undertaken globally to remediate this challenge by incor- porating both chemical and green technology processes with up-to-date developments in both industry and science [2]. Silver nanoparticles have displayed diferent chemical, physical and biological properties due to their high surface area and small particle sizes [3]. As a result of their shape, non-toxic nature and size-dependent characteristics, AgNPs have found application in various felds such as water treat- ment [4], as antimicrobial agents [5] and as catalysts [6]. In particular, AgNPs have received much attention as antimi- crobial agents as they present very strong bactericidal action against a broad spectrum of bacteria [7]. Most products that have incorporated silver nanoparticles such as cosmetics [8], wound dressings [9], medical implants [10] are considered safe [11]. In addition to fnding application in consumables, plant synthesized silver nanoparticles have also been applied in wastewater treatment since it is a simple, cost efective, and efcient method for removal of organic pollutants [12]. AgNPs can be synthesized by employing either physical or chemical approach with physical approaches exploiting numerous methods such as laser ablation and condensation/ evaporation. In chemical approach, metal ions in resulting solutions are reduced in settings favoring successive forma- tion of smaller metal clusters or even agglomerates. Some of the reducing agents employed in chemical synthesis include sodium borohydride, tollens reagent, sodium citrate, etc. [13]. The production of toxic chemicals, difculties in purifcation and high energy consumption are some of the factors that hinders application of chemically synthesized nanoparticles in various felds [14]. * A. O. Nyabola nyabolaaugustine@gmail.com 1 Chemistry Department, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000, Nairobi 00200, Kenya