Localized surface plasmon resonance-optical sensors based on radiolytically synthesized silver nanoparticles for estimation of uric acid

The quantitative determination of trace levels of uric acid has potential applications in the medical field. In this work, a simple colorimetric estimation of uric acid based on localized surface plasmon resonance (LSPR) band of polyvinyl pyrrolidone-capped-silver nanoparticles (PVP-Ag-NPs) is described. PVP-Ag-NPs were synthesized via gamma radiolytic route, thereby, avoiding the use of any external chemical reducing agent. These nanoparticles were characterized using UV-visible spectrophotometry, transmission electron microscopy (TEM), atomic force microscopy (AFM) and particle size analyzer (PSA). The silver nanoparticles prepared by this method were found to be of spherical shape with diameters 5.1 +/- 1.6 nm. Radiation synthesized silver nanoparticles were then used as LSPR-based optical chemical sensors for detection and estimation of uric acid concentrations in human serum and bovine serum samples. The effect of PVP molecular weight on the uric acid detection efficiency of the system was also studied. It was observed that low molecular weight PVP (40 kD) gave better results as biosensor for uric acid estimation. (c) 2013 Elsevier B.V. All rights reserved.