Helical silver(I)-glutathione biocoordination polymer nanofibres.

Helical nanofibres of silver(I)-glutathione (Ag-GSH) biocoordination polymer (BCP) are fabricated by introducing dimethyl sulfoxide into the mixture solution of Ag⁺ ions and L-GSH molecules. The prepared BCP nanofibres show hierarchical helical structures, which are constructed via twisting of small fibres. Water-soluble helices could be further cross-linked with Ca²⁺ ions to form a well-dispersed aqueous suspension. When gold nanorods are adsorbed onto these helical nanofibres, the unique plasmon-induced circular dichroism characteristic is observed in the region of the local surface plasmon resonance of gold nanorods. This type of chiroptical metamaterials may have promising applications in nonlinear optics, negative refraction and biosensing.