Dual-functional porphyrinic zirconium-based metal–organic framework for the fluorescent sensing of histidine enantiomers and Hg 2+

l -Cys/PCN-222 as a novel and dual-functional fluorescent sensor was developed. It not only showed a higher chiral fluorescent recognition of l -histidine but also performed as a visual sensor for Hg 2+ in actual surface water.