Synthesis of a pyridyl-appended calix[4]arene and its application to the modification of silver nanoparticles as Fe3+ colorimetric sensor

A novel pyridyl-appended calix[4]arene, which can selectively bind Fe3+, was synthesized via click chemistry. The calix[4]arene was employed to synthesize silver nanoparticles with a distinct colorimetric response to Fe3+, due to the complexation of Fe3+ ion with calix[4]arene inducing aggregation of Ag NPs.