Figure 3

Selectivity test of the R6G/MPA-NPG sensor.

(a) Normalized fluorescence change of R6G with individual metal ions at various concentrations. (b) The normalized fluorescence intensities with various mixed ions at different concentrations. The rhomb dots indicate the solution only contains Hg²⁺. The inverted triangle dots (mixed) indicate the solution contains Hg²⁺, Ag⁺, Mn²⁺, Mg²⁺, Ca²⁺, K⁺ and Ba²⁺ with the same concentrations and the square dots (super-mixed) indicate the solution contains Hg²⁺, Ag⁺, Mn²⁺, Mg²⁺, Ca²⁺, K⁺, Ba²⁺, Cu²⁺, Cr²⁺, Na⁺, Co²⁺, Zn²⁺ and Pb²⁺ with the same concentration. Excitation wavelength is 532 nm.