One-step synthesis of lignosulfonate-stabilized silver nanoparticles.

Softwood lignosulfonate (SLS) was used as a reducing agent for one-step synthesis of silver nanoparticles (SLS-AgNPs) in an aqueous solution at room temperature. In this reaction SLS acts also as a stabilizing agent and as a result, stable colloids of silver nanoparticles are formed during the reaction with the average particle size of 41 nm. The obtained SLS-AgNPs were characterized by UV-vis spectrophotometry, size distribution and AFM imaging after casting on mica. Due to metal ion complexing capability of lignosulfonates, the SLS-AgNPs appeared to be capable of colorimetric detection of metal ions (especially nickel). Additionally, the SLS-AgNPs could be assembled into thin films on conducting substrates (ITO glass) using electrophoretic deposition. XPS spectroscopy was used to characterize such films and revealed a strong interaction of silver atoms with some carbon atoms of the SLS.