Facile preparation of Ag nanoparticles using uric acid and their applications in colorimetric detection and catalysis

Abstract

In this study, we have reported a facile, cost-effective method for the synthesis of silver nanoparticles (Ag NPs) using uric acid (UA) as the reducing agent. Techniques such as UV-visible spectroscopy, transmission electron microscopy and X-ray spectroscopy were performed to characterize the generated UA–Ag NPs. UA–Ag NPs exhibited excellent specificity towards Ba²⁺ and Sr²⁺, which could be traced by UV-visible spectra and the naked eye; we also obtained the lowest detection limits of 52.1 nM and 27.5 nM for Ba²⁺ and Sr²⁺, respectively. The proposed method provided sensitive and rapid detection of Ba²⁺ and Sr²⁺ at the nM level in water samples, and the values were much lower than the U. S. EPA standard for the maximal limits of these metal ions in drinking water. UA–Ag NPs could be employed as a colorimetric probe to assay Ba²⁺ and Sr²⁺ in lake water, indicating their potential applicability for detection in real samples. As far as we know, this is the first attempt for the colorimetric detection of Sr²⁺ by noble metal nanoparticles. Furthermore, UA–Ag NPs exhibited excellent potential for catalyzing the reduction of nitrophenols and potassium ferricyanide.