Critical Parameters of Silver Nanoparticles (AgNPs)synthesized by Sodium Borohydride Reduction

Nanoparticle technology has rapidly developed during the past few years. The Center for Radioisotope and Radiopharmaceutical Technology (PTRR), National Nuclear Energy Agency (BATAN) developed silver nanoparticles (AgNPs) that can be applied in the medical field through Iodine-125 labeling. There are numerous methods for AgNPs synthesis, but details of important parameters in the synthesis are not available. This study aims to learn the simplest approach to AgNPs synthesis and to determine the critical parameters of stable AgNPs. The synthesis of AgNPs was performed by the reduction method. Silver nitrate was reduced using sodium borohydride and stabilized by using polyvinylpyrrolidone (PVP) and NaCl. The critical parameters observed in this study were reducing agent, stabilizer effect and pH. Analysis of AgNPs was performed using a UV-Vis Spectrophotometer, Transmission Electron Microscopy (TEM), Particle Size Analyzer (PSA) and Zeta Potential. The stable AgNPs formation demonstrated a clear yellow solution at a pH of 8 without any sediment. The Surface Plasmon Resonance peaked at around 400 nm by UV-Vis Spectrophotometer analysis. The AgNPs size was measured using TEM which was found to be 20 nm. The analysis using PSA showed that the polydispersity index was 0.369 whereas for Zeta Potential it was -15.93 mV. The presence of reductor and stabilizer had an impact on the product stability. In the simplest approach of stable AgNPs, synthesis must be in exact composition of silver nitrate (1mL, 0.001 N), reductor NaBH4 (1 mL, 0.002N), 40 mL PVP 0.3% (w/v) and 20 mL NaCl 1.5 N, without stirring and temperature setting.