Chicken egg white and L-cysteine as cooperative ligands for effective encapsulation of Zn-doped silver nanoclusters for sensing and imaging applications

Abstract

Herein, we report chicken egg white (CEW) and L-cysteine (L-Cys) as cooperative ligands for effective encapsulation of Zn-doped silver nanoclusters (Zn-doped Ag NCs) for enhancing optical properties in sensing of Hg2+ ion and bioimaging of fungal cells (Alternaria sp.). The emission peak at 657 nm was remarkably enhanced by doping of Zn-atom into Ag NCs, suggesting the proteins of CEW and L-Cys provide good architectures for supramolecular encapsulation of Zn-Ag NCs. The quantum yield (QY) of Ag NC was improved to 13.3% due to the doping of Zn atoms into Ag NCs. The “fluorescence-off” of Zn-doped Ag NCs is proceeded by the addition of Hg2+ ion, which exhibits detection limit of 68 nM. The other chemical species did not interfere with assay of Hg2+ ion. We also extended the application of Zn-doped Ag NCs as a probe in imaging of fungal cells (Alternaria sp.). The CEW-L-Cys encapsulated Zn-doped Ag NCs exhibited an excellent stability and shown to be a magnificent probe for sensing and bioimaging applications, which demonstrates that Zn-doped Ag NCs as potential candidates in analytical and bioanalytical sciences.