A phenylphenthiazide anchored Tb(III)-cyclen complex for fluorescent turn-on sensing of ClO−

A phenylphenothiazine anchored Tb(III)-cyclen complex PTP-Cy-Tb for hypochlorite ion (ClO−) detection has been designed and prepared. PTP-Cy-Tb shows a weak Tb-based emission with AIE-characteristics in aqueous solutions. After addition of ClO−, the fluorescence of PTP-Cy-Tb gives a large enhancement for oxidization the thioether to sulfoxide group. The detection limit of PTP-Cy-Tb toward ClO− is as low as 8.85 nmol/L. The sensing mechanism was detailedly investigated by time of flight mass spectrometer (TOF-MS), Fourier transform infrared spectroscopy (FT-IR) and density functional theory (DFT) calculation. In addition, PTP-Cy-Tb has been successfully used for on-site and real-time detection of ClO− in real water samples by using the smartphone-based visualization method and test strips.