Fig. 2From: Fabrication of avidin-stabilized gold nanoclusters with dual emissions and their application in biosensingOptimum concentration of HAuCl4 for the synthesis of Av–Au NCs. A Fluorescence emission spectra for Av–Au NCs synthesized from different concentrations of HAuCl4 with excitation at 374 nm. Slit widths of excitation: 10 nm, slit widths of emission: 10 nm, and voltage: 700 V. B Fluorescence emission curves of 24 h and 48 h Av–Au NCs synthesized from 1.0 mM HAuCl4 as a raw material. Slit widths of excitation: 10 nm, slit widths of emission: 5 nm, and voltage: 700 V. C Fluorescence emission spectra for Av–Au NCs synthesized from different concentrations of HAuCl4 with excitation at 295 nm. Slit widths of excitation: 5 nm, slit widths of emission: 5 nm, and voltage: 650 V. D Optical absorption spectra of Av–Au NCs synthesized from different concentrations of HAuCl4. Different concentrations of HAuCl4 were allowed to react in a 38 °C water bath for 10 hBack to article page