Current Trends in Natural Sciences Vol. 10, Issue 20, pp. 53-60, 2021 https://doi.org/10.47068/ctns.2021.v10i20.008 Current Trends in Natural Sciences (on-line) Current Trends in Natural Sciences (CD-Rom) ISSN: 2284-953X ISSN: 2284-9521 ISSN-L: 2284-9521 ISSN-L: 2284-9521 http://www.natsci.upit.ro *Corresponding author, E-mail address: soleil_cri@yahoo.com 53 CHARACTERIZATION IN TERMS OF COMPOSITION AND PHYTOTOXICITY OF AQUEOUS SPORES EXTRACT Oana-Alexandra Drăghiceanu 1 , Anca Nicoleta Șuțan 1 , Codruța Mihaela Dobrescu 1 , Nicoleta Doruța Bătut-Andrei 1 , Liliana Cristina Soare 1* , Carmen Mihaela Topală 1 1 University of Pitești, Târgu din Vale Street, 110040, Pitești, România Abstract In this study, we used aqueous extracts of fern spores and solution of AgNO 3 and HAuCl 4 for the synthesis of bimetallic nanoparticles Au:Ag in different proportions: 1:1 and 1:10. The spores used come from 2 species of ferns: Asplenium scolopendrium and Dryopteris filix-mas. For the characterization of the extracts with or without bimetallic nanoparticles we applied Fourier transform infrared spectroscopy (FT-IR). Phytotoxicity was tested using Pisum sativum seeds. Each extract was tested in 2 dilutions: 1:10 (D10) and 1:100 (D100). The parameters, which we determinate were the root and stem growth and fresh biomass. Root growth was stimulated in variants with Asplenium scolopendrium extract: without nanoparticles both dilution and with Au:Ag nanoparticles 1:10 D10. The highest values obtained for the stem were at D10 at the variants with Asplenium scolopendrium extract with or without bimetallic nanoparticles. The influence of extracts on fresh biomass was smaller than on the growth of root and stem. Keywords: bimetallic nanoparticles, extracts, fern spores, FT-IR, Pisum sativum. 1. INTRODUCTION Because of their unique physical and chemical properties, nanoparticles (NPs) are used in numerous biological, chemical, optical and electronic applications (Rahman et al., 2020). Green synthesis of nanoparticles it is simple, clean, safe and environmentally friendly (Rani et al., 2022). Having antibacterial and biocidal properties, Ag NPs are frequently used in medical application, cosmetics and food services (Jogaiah et al., 2021). AuNPs are easy to synthesize and are stable; they may have different size and relatively low toxicity. AuNPs can be used as an agent for gene/drug delivery because they have small size they can enter in the cell by endocytosis or diffusion (Kumar et al., 2018). Metal combinations are another important subject that has been in the attention of researchers due to their new characteristics different from the properties of the components (Dobrucka et al., 2021). Green synthesized bimetallic Au-Ag nanoparticles have interesting properties and higher catalytic efficiencies than Au and Ag monometallic nanoparticles (Sahu et al., 2020). Ten years before the beginning of the nano-ecotoxicology field, researchers said that NPs can have a negative effect on biota by generating ROS (Khan et al., 2021). Plants are one of the most important forms of life because they are the primary producers in the ecosystem. The effect of nanoparticles on plants varies upon their concentrations, properties (physical and chemical) and