Synthesis of Colloidal Silver Nanoparticles Using Alginate as Reducing and Stabilizing Agent and its Application as Antibacterial Material
Endang Susilowati, Lina Mahardiani, Sri Retno Dwi Ariani, and Hidayat Fauzi

Universitas Sebelas Maret

Abstract

Colloidal silver nanoparticles (AgNps) were synthesized using AgNO3 as precursor, NaOH as accelerator reagent and alginate as reducing agent as well as stabilizer. The effect of temperature, accelerator concentration, time and precursor concentration were investigated based on localized surface plasmon resonance (LSPR) phenomenon using UV-Vis spectrophotometer. The size distribution of nanoparticles were observed using Particle Size Analyzer (PSA). The stability of silver-alginate nanocomposites were tested for 8 weeks based on the LSPR phenomenon. Colloidal AgNps were tested for their antibacterial activity against S. Aureus ATCC 25923 and E. Coli ATCC 25922. The result showed that the number of silver nanoparticles formed were influenced by temperature, time, NaOH concentration, and AgNO3 concentration. At a temperature of 50C, the optimum synthesis of silver-alginate nanocomposites at 50 minutes with concentration of 0.013M NaOH. The higher the AgNO3 concentration, the higher the concentration of silver nanoparticles formed. Based on result of PSA characterization showed that the particle size in the range 0.8 - 5.0 nm. Based on the LSPR phenomenon, colloidal AgNps were stable in storage for 8 weeks at room temperature. The increase in concentration of silver nanoparticle within colloidal will increase antibacterial activity against S. Aureus and E. Coli. Silver-alginate nanocomposites have the potential to be used as an antibacterial material for medical applications.

Keywords: Colloidal, silver nanoparticles, alginate, antibacterial

Topic: Material and Applied Chemistry