Sensing properties of silica nanoparticles functionalized with anion binding sites and sulforhodamine B as fluorogenic signalling unit

► Functionalized silica nanoparticles for anion sensing have been prepared. ► Silica nanoparticles coated with imidazolium and sulforhodamine groups selectively recognize I− and BzO−. ► Silica nanoparticles coated with guanidinium and sulforhodamine groups selectively recognize HSO4− and H2PO4−.