STUDIA UBB CHEMIA, LXIII, 4, 2018 (p. 95-102) (RECOMMENDED CITATION) DOI:10.24193/subbchem.2018.4.07 EVALUATION OF CAPPING AGENTS FOR SILVER NANOPARTICLES CRISTIAN T. MATEA a , TEODORA MOCAN a, b, * , FLAVIU TABARAN a, c , TEODORA POP d , OFELIA MOSTEANU d , LUCIAN MOCAN a, e , CLAUDIU ZDREHUS e ABSTRACT. We have synthetized silver nanoparticles capped with: citrate, mercaptosuccinic acid, and thioctic acid respectively. Each of the obtained nanoparticles were characterized by means of: UV-Vis and ATR-FT-IR spectroscopy, dynamic light scattering (DLS), atomic force microscopy (AFM) and were found to be spherical in shape and aqueous stable. Keywords: silver nanoparticles, capping agents, citrate, mercaptosuccinic acid, thioctic acid INTRODUCTION Silver nanoparticles (AgNPs), with their localized surface plasmon resonance (SPR) and remarkable antimicrobial properties have been a research focal point in the field of life sciences, for the past decade [1-4]. Several studies showed that the activity of noble metal nanoparticles, such as AgNPs, is strongly correlated with their colloidal stability [5, 6]. Special consideration must be given to the stabilization agents used for the synthetized nanoparticles. For example, divalent cations can induce AgNP aggregation by displacing the capping citrate layer [7], also pH significantly influences the stability of a AgNPs suspensions [8]. Adequate functionalization strategies must be undertaken in order to obtain nanostructures with specific characteristics for each biomedical application envisioned. These strategies can be divided into four a Department of Nanomedicine “Octavian Fodor” Gastroenterology Institute, Cluj-Napoca, Romania. b Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania. * Corresponding author: teodora.mocan@umfcluj.ro c Department of Pathology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine. d 3rd Gastroenterology Department “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania. e 3rd Surgery Clinic “Iuliu Hatieganu” University of Medicine and Pharmacy Cluj-Napoca Romania.