Gold-Carboxymethyl Cellulose Nanocomposites Greenly Synthesized for Fluorescent Sensitive Detection of Hg(II)

The green synthesis of gold nanoparticles, using carboxymethyl cellulose as both capping agents and reducing agents, is an environmental friendly, simple and efficient route for synthesis of metallic nanoparticles. The optimal conditions, such as the ratio of 0.5 mM HAuCl4 against 0.4% CMC; temperature 80 A degrees C; solution pH 9.0 and reaction duration 50 min, were established to produce the narrower distribution, the smaller and more stable AuNPs-CMC. The spherical gold nanoparticles-carboxymethyl cellulose nanocomposites (AuNPs-CMC) with an average particle size of 20.3 +/- 5.5 nm was confirmed by the techniques such as high transmission electron microscopy, energy dispersive X-ray spectroscopy, selected area electron diffraction pattern and dynamic light scattering. The as-synthesized AuNPs-CMC with a SPR absorption band of 522 nm can be used as fluorescent probes for the detection of Hg(II) in the range of 0.05-0.32 mu M with a detection limit of 3.6 nM. This study essentially paves the way for the generation of functional materials with coupled optical properties and as an analytical platform for rapid and selective detection of metal ions.