Design and Synthesis of Dipeptidomimetic Isocyanonaphthalene as Enhanced-Fluorescent Chemodosimeter for Sensing Mercury Ion and Living Cells.

A novel valine-based isocyanonaphthalene () was designed and synthesized by using an easy method and enabled the selective fluorescence detection of Hg. The chemodosimeter can display an immediate turn-on fluorescence response (500-fold) towards target metal ions upon the Hg-mediated conversion of isocyano to amino within . Based on this specific reaction, the fluorescence-enhancement probe revealed a high sensitivity toward Hg over other common metal ions and exhibited excellent aqueous solubility, good antijamming capability, high sensitivity (detection limit: 14.2 nM), and real-time detection. The response mechanism of was supported by NMR spectroscopy, MS analysis and DFT theoretical calculation using various techniques. Moreover, a dipeptidomimetic probe was successfully applied to visualize intracellular Hg in living cells and monitor Hg in real water samples with good recoveries and small relative standard deviations.