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.