AIE biofluorescent probe based on twisted cucurbit[14]uril for the detection of Fe(CN)63- anion in solutions and live kidney cells

The kidney is one of the important organs for removing metabolites to maintain the stability of the internal environment. In this study, an AIE effect supramolecular fluorescent probe (TPAPy@tQ[14]) was constructed based on twisted cucurbit[14]uril (tQ[14]) and a triphenylamine derivative (TPAPy) through host-guest interaction. TQ[14] could effectively inhibit the rotation of the TPAPy molecule, which triggered the AIE effect. This effect was manifested as the emission of bright yellow fluorescence. TPAPy@tQ[14] could ultrasensitively detect potential cyanide (K3[Fe{CN}6]) in an aqueous solution at a detection limit as low as 3.28 × 10−7 M. The unique nature of the positive charge of TPAPy@tQ[14] could rapidly cross the glomerular filtration barrier into HK-2 cells. In addition, this probe was successfully applied to distinguish excess Fe(CN)63− in HK-2 cells for cell imaging, providing a new detection method for early clinical identification of acute kidney injury (AKI).