A plasmonic nano-sensor for the fast detection of Ag+ based on synergistic coordination-inspired gold nanoparticle

Silver is one of most important heavy metals, which affects the environment and organism significantly along with its widespread applications. An interesting gold nanoparticles (AuNPs)-based system, in this work, was fabricated using the adenosine and creatinine for the colorimetric recognition of the Ag+ via a red-to-blue color change. A synergistic coordination of these two biomolecules with Ag+ on AuNPs' surface supplied an excellent selectivity than examples by a single ligand-modified AuNPs in literatures. It realized a qualitative Ag+ recognition by naked eyes in aqueous media, as well as a quantitative determination by the UV-vis spectrometer over a range of 0.1-0.9 μM, covering the Ag+ standard in drinking waters (0.46 μM, US Environmental Protection Agency). This system is not only convenient but also very sensitive with a limit detection of 7.3 nM. This platform is applicable for the Ag+ recognition in mimic pollution samples with a good repeatability and relative standard deviation.