One‐pot strategy for biomimetic synthesis of zein‐conjugated silver sulphide nanospheres in ethanol solution

Water‐soluble Ag 2 S nanospheres embedded in a zein matrix were successfully synthesised by a simple, controllable protein‐assisted method in ethanol solutions. The morphology and size of products were tunable through controlling the concentration of zein. X‐ray diffraction and energy‐dispersive X‐ray spectrum results showed that the obtained samples were a pure monoclinic phase of Ag 2 S. The Ag 2 S nanoparticles were homogeneously surrounded by protein molecules observed from a high‐resolution transmission microscopy image. There was strong chemical interaction between the Ag 2 S nanocrystals and the functional groups of zein molecules, which has been confirmed by Fourier transform infrared and thermogravimetry analysis measurements. The band gap of zein‐conjugated Ag 2 S nanocrystals showed obvious blue shift in ultraviolet‐visible spectra compared with bulk materials because of the quantum size effect.