Organic-Inorganic Hybrid Pillarene-Based Nanomaterial for Label-Free Sensing and Catalysis

Carboxylatopillar[6]arene sodium salt was used as an efficient reducing agent and stabilizer for the colloidal synthesis of gold nanoparticles coated with a nanoporous layer of synthetic macrocycles via the reversed Turkevich method. The carboxylatopillar[6]arene-functionalized nanoparticles were assembled in a controlled fashion utilizing the host-guest interactions between carboxylatopillar[6]arene and a cationic guest. Significantly, label-free detection of the widely used herbicide paraquat (methyl viologen) was achieved, whereby two different methods of spectral analysis were combined to reduce the detection limit and extend the concentration range of detection. Furthermore, the carboxylatopillar[6]arene-functionalized nanoparticles exhibited efficient catalysis of the reduction of nitrophenols. This facile, one-pot synthesis will be useful for future studies of organic-inorganic hybrid nanomaterials and applications in sensing and catalysis.