Highly Sensitive Ratiometric Fluorescent Chemosensor for Silver Ion and Silver Nanoparticles in Aqueous Solution

A pyrene derivative chemosensor (<b>Pyr-WH</b>) based on a dipeptide shows a highly sensitive ratiometric response to Ag(I) as well as silver nanoparticles in aqueous solution at physiological pH. <b>Pyr-WH</b> penetrated live HeLa cells and exhibits a ratiometric response to intracellular Ag(I). The binding mode of <b>Pyr-WH</b> with Ag(I) was characterized based on fluorescence changes in different pH, NMR, and ESI mass spectrometer experiments