Silver nanoparticles stabilized by ramnolipids: Effect of pH

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 205; p. 111883
• Main Authors: Salazar-Bryam, Ana Maria, Yoshimura, Ingrid, Santos, Larissa Provasi, Moura, Cinthia Cristine, Santos, Caio Carvalho, Silva, Vinicius Luiz, Lovaglio, Roberta Barros, Costa Marques, Rodrigo Fernando, Jafelicci Junior, Miguel, Contiero, Jonas
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2021
• Subjects: antimicrobial properties; Biosurfactant; biosurfactants; carbon; glycerol; Glycolipid; Metallic nanoparticles; Micelles; nanobiotechnology; Nanomaterials; nanosilver; rhamnolipids; Vesicles; zeta potential; Biosurfactant; Nanomaterials; Vesicles; Metallic nanoparticles; Micelles; Glycolipid
• ISSN: 0927-7765; 1873-4367; 1873-4367
• DOI: 10.1016/j.colsurfb.2021.111883

[Display omitted] •Production and characterization of ramnolipids from glycerol.•Synthesis of silver nanoparticles.•Influence of pH on the shape and size of nanoparticles.•Characterization of silver nanoparticles. Rhamnolipids are glycolipid biosurfactants that have remarkable physicochemical characteristics, such as the capacity for self-assembly, which makes these biomolecules a promising option for application in nanobiotechnology. Rhamnolipids produced from a low-cost carbon source (glycerol) were used to stabilize silver nanoparticles. Silver nanoparticles (AgNPs) have been the subject of studies due to their physical chemical as well as biological properties, which corroborate their catalytic and antimicrobial activity. We compared nanoparticles obtained with three different pH values during synthesis (5, 7 and 9) in the presence of rhamnolipids. Dynamic light scattering showed that larger particles were formed at pH 5 (78–190 nm) compared to pH 7 (6.5–43 nm) and 9 (5.6–28.1 nm). Moreover, nanoparticle stability (analyzed based on the zeta potential) was enhanced with the increase in pH from 5 to 9 (−29.86 ± 1.04, −37.83 ± 0.90 and −40.33 ± 0.57 mV, respectively). Field emission gun scanning electron microscopy confirmed the round morphology of the silver nanoparticles. The LSPR spectra of AgNP for the pHs studied are conserved. In conclusion, different pH values in the presence of rhamnolipids used in the synthesis of silver nanoparticles directly affect nanoparticle size and stability.