Green synthesis of silver nanoparticles mediated by plant extracts: a critical review and experimental insights on the integrated effects of pH, temperature, and concentration
Year: 2026
Type: article
Abstract: Plant-extract-mediated green synthesis of silver nanoparticles (AgNPs) has emerged as a promising and sustainable approach aligned with the demand for environmentally responsible methods. This study critically reviews key physicochemical parameters pH, temperature, and reagent concentration that govern AgNP morphology, colloidal stability, and functionality. Alkaline conditions and moderate temperatures may enhance silver-ion reduction and colloidal stabilization, whereas plant-extract concentration must be carefully adjusted to balance nucleation, growth, and surface capping. A case study using Astrocaryum aculeatum extract at 10, 15, 20, and 30 g L ⁻1 was evaluated by UV–Vis spectroscopy, dynamic light scattering (DLS), polydispersity index (PDI), and nanoparticle tracking analysis (NTA). Based on three independent synthesis batches, samples prepared with 10, 15, and 20 g L ⁻1 extract exhibited SPR maxima at 406.3 ± 3.2, 410.0 ± 2.0, and 407.0 ± 1.0 nm, respectively, whereas no clearly resolved SPR maximum was observed at 30 g L ⁻1 . Increasing the extract concentration from 15 to 30 g L ⁻1 increased the mean hydrodynamic diameter from 220.0 ± 19.0 to 786.3 ± 108.8 nm and the PDI from 0.338 ± 0.015 to 0.939 ± 0.050. Extract concentration significantly affected PDI [F(3,8) = 160.50, p < 0.001], with a marked increase between 15 and 20 g L ⁻1 . NTA showed the highest particle-number concentration at 15 g L ⁻1 , reaching (5.41 ± 0.18) × 10 10 particles mL ⁻1 . These results identify 15 g L ⁻1 as the most favorable concentration among the tested conditions. Overall, this review provides practical guidance for defining system-specific synthesis conditions and highlights the importance of extract standardization and complementary colloidal characterization for reproducible AgNP production.
Source: Bioscience Nanotechnology
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,790
Awards: CDMF - Center for the Development of Functional Materials, Development of multifunctional hybrid supraparticles as potential sustainable material for agrochemicals, Development of novel magnetic nanocomposites based on hydrogel for evaluation as carrier vehicle of drugs and agricultural inputs, Study of novel biodegradable carrier vehicles of fertilizers and agricultural defensives based on hydrogel and nanostructure silicates as an alternative in the combat of environmental impacts
OpenAlex ID: W7203931364