Fig. 5. (A) This method was used to detect some metal ions, including Hg²⁺, Zn²⁺, Mn²⁺, Cd²⁺, Cr³⁺, Mg²⁺, Al³⁺, Cu²⁺, Ni²⁺, Fe³⁺, Ca²⁺, Pb²⁺ ions. (B) Corresponding images. The concentration of Hg²⁺ ions was 1 μM, and other metal ions were all 10 μM.