Figure 3.

a Fluorescence spectra of solutions of 100 μL BSA-GNPs on addition of 400 μL other ions (500 μM Cd2+, Cr3+, Ba2+, Zn2+, Ca2+, Mn2+, Mg2+, Fe2+, Co2+, 50 μM Ni2+, Cu2+, Pb2+ and 4 μM Hg2+. b Enhanced ratios (I/I0) of the fluorescence intensity (640 nm) of solution in (a). Excitation wavelength: 470 nm. c Fluorescence photographs of 100 μL BSA-GNPs upon addition of 400 μL of other ions other ions (50 μM) and Hg2+ (4 μM)

Chai et al. Nanoscale Research Letters 2010 5:1856-1860   doi:10.1007/s11671-010-9730-y