Green synthesis of silver nanoparticles by chemical reduction with hyaluronan

The paper reported a facile and green synthesis of silver nanoparticles by using hyaluronan (HA) as a reducing agent and soft template. The effect of reaction conditions on the Ag nanoparticle formation was investigated using UV-vis spectrophotometer, field-emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The application of Ag nanoparticles in surface enhanced Raman scattering (SERS) of HA was also evaluated. The results showed that the high pH value, temperature and molar ratio of HA to AgNO3 could accelerate the reduction rate of Ag+ and affect the Ag nanoparticle size. The Ag nanoplates could be fabricated with a low molar ratio of HA to AgNO3 by aging, which may be due to the selective adsorption and desorption of HA on the different crystallographic planes of Ag nanoparticles. The enhancement of Raman scattering effect was greatly dependent on the size and morphology of Ag nanoparticles.