Inclusion of guest materials in aqueous coordination network shells spontaneously generated by reacting 2,5-dimercapto-1,3,4-thiadiazole with nanoscale metallic silver

Abstract

Noble metal nanoparticles (NPs) are spontaneously enfolded by aqueous coordination networks generated by reacting 2,5-dimercapto-1,3,4-thiadiazole (DMcT) with silver nanostructures in zero-oxidation state, and finally form novel hollow Au@Ag@infinite coordination polymers core–shell nanostructures (Au@Ag@void@ICPs). In this synthesis, DMcT molecules not only act as the bridging ligands but also directly oxidize Ag⁰ to Ag⁺ ions for the formation of amorphous DMcT–Ag ICPs. And, the sizes of the shell and void of Au@Ag@void@ICPs can be facilely tuned by modulating the amount of DMcT and the size ratio of Au@Ag NPs, respectively. Due to the high structural tailorability of DMcT–Ag ICPs, multi-encapsulation of Au@Ag NPs with either small organic molecules or biological macromolecules (e.g., enzymes) can be achieved to fabricate multi-functional core–shell nanostructures. A case in point is that a highly sensitive biosensor of H₂O₂ with a wider detection window has been constructed based on the prepared metal NPs–ICPs–enzyme composites and resonance Raman scattering. This study provides not only a new template for tailoring hollow core–shell nanomaterials but also a versatile platform for chemical (bio) sensing.