A fast, sensitive and stable fluorescent fiber-optic chemosensor for quantitative detection of Fe3+ in real water and HepG2 living cells

Based on the fluorescence quenching mechanism of Fe 3+ to moxifloxacin (MOX), a fluorescence probe has been found and exhibits high sensitivity, unique selectivity and good stability toward Fe 3+ . Moreover, the MOX probe can rapidly response to the change of Fe 3+ concentration in pure aqueous solution. The MOX probe was utilized for quantitative determination of Fe 3+ in real water sample, showing a good linear relationship ( R   =   0.9980) between (F 0 –F) and [Fe 3+ ] 1/2 at the Fe 3+ concentration from 0.05–15   μM. The detection limit was found to be 0.032   μM, which is much lower than that of most literature reported. Furthermore, by merging the MOX probe and a Y-tape fiber-optic spectrometer, a fluorescent fiber-optic chemosensor has been developed to quantitatively monitor Fe 3+ in HepG2 living cells in vivo. The monitoring results are consistence with that obtained from the confocal imaging technique. The established method possesses the advantages of fast responsive, high sensitivity, unique selectivity, very stability and good repeatability for quantitative monitoring Fe 3+ in real water and HepG2 living cells. In addition, the complex mechanism of MOX toward Fe 3+ has also been explored by Fourier transform infrared spectroscopy (FT-IR) and mass spectra (MS) in the present work.