DEVELOPMENTS IN MS&E Phytosynthesis and radiation-assisted methods for obtaining metal nanoparticles Radu Claudiu Fierascu 1 , Irina Fierascu 1, * , Eduard Marius Lungulescu 2 , Nicoleta Nicula 2 , Raluca Somoghi 1 , Lia Mara Dit ¸u 3 , Camelia Ungureanu 4 , Anca Nicoleta Sutan 5 , Oana Alexandra Dra ˘ ghiceanu 5 , Alina Paunescu 5 , and Liliana Cristina Soare 5 1 Emerging Nanotechnologies Group, National Institute for Research and Development in Chemistry and Petrochemistry – ICECHIM Bucharest, 202 Spl. Independentei, 060021 Bucharest, Romania 2 Department of Metallic Composite and Polymeric Materials, National Institute for R&D in Electrical Engineering ICPE – CA, 313 Spl. Unirii, 030138 Bucharest, Romania 3 Microbiology Department, University of Bucharest, 1-3 Aleea Portocalelor, 060101 Bucharest, Romania 4 Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, 1-7 Ghe. Polizu Str., 011061 Bucharest, Romania 5 Department of Natural Sciences, University of Pitesti, 1 Targu din Vale Str., Pitesti, 110040 Arges, Romania Received: 2 April 2019 Accepted: 21 May 2019 Ó Springer Science+Business Media, LLC, part of Springer Nature 2019 ABSTRACT Metallic nanoparticles represent an important area of research, as their unique properties can be tuned for the desired application. Several ‘‘green’’ methods were proposed for obtaining metallic nanoparticles, including phytosynthesis (using natural extracts) and radiation-assisted synthesis. The present work studies the differences in terms of biological properties (antimicrobial proper- ties, cytotoxicity and phytotoxicity) of silver nanoparticles obtained using those two very different approaches. The obtained nanoparticles were analytically characterized using transmission electron microscopy, X-ray diffraction and UV–Vis spectrometry, for the evaluation of their morphological properties, which can be linked to their biological properties. The results showed that the radiation-assisted path led to smaller dimension nanoparticles (7–10 nm), while the phytosynthesis led to nanoparticles with 10–12 nm in diameter (as deter- mined by XRD), depending on the used materials. The phytosynthesized nanoparticles seemed to be more effective antimicrobial agents (effect studied against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231), while those obtained by the radiological path had a stronger mitoinhibitory effect. The growth of the root and of the stem was less affected by the samples containing radiological synthesized nanoparticles. Radu Claudiu Fierascu, Irina Fierascu, Eduard Marius Lungulescu and Anca Nicoleta Sutan have an equal contribution to the present paper and are considered main authors. Address correspondence to E-mail: dumitriu.irina@yahoo.com https://doi.org/10.1007/s10853-019-03713-3 J Mater Sci Developments in MS&E