A lysosome-targeting probe for dynamic Fe3+ tracking and the probe-Fe3+ imaging applications in living cells

Through an opening-closing transformation of the spirolactam ring in the rhodamine moiety, the rhodamine-based probe J2 could accomplish 1:1 binding towards the target Fe3+ with high selectivity and sensitivity. Further theoretical calculations labelled the combination atoms to capture Fe3+ in J2 and revealed the possible recognition mechanism of J2-Fe3+. Accompanied the combination of probe J2 and Fe3+ were not only obvious color differences but fluorescence changes, which enabled both naked-eye detections of aqueous Fe3+ by J2 and the bioimaging applications of J2-Fe3+ in living cells. Besides, low cytotoxicity, cell permeability and lysosome accumulation for probe J2, suggested its future applications for instant detection and dynamic tracking of lysosome Fe3+ in the autophagy lysosome monitoring or a related clinical diagnosis.