A novel “OFF–ON–OFF” fluorescence chemosensor for hypersensitive detection and bioimaging of Al(Ⅲ) in living organisms and natural water environment

High-selectivity detection of trace Al 3+ ions in water and biological systems by a fluorescence imaging method is not yet mature. Herein, we synthesized a novel reversible Al 3+ -specific fluorescent probe named RBLF by linking Rhodamine B and pyridine-3-sulfonyl chloride through o-phenylenediamine in several reactions. RBLF exhibited an ultra-high sensitive and excellent selective response towards Al 3+ by fluorescence and UV–vis spectra in aqueous solutions. What is more worth mentioning is that its response is fast, dual changes in color and fluorescence of the probe solution that can occur instantaneously after adding with Al 3+ . Its detection limit for Al 3+ ions in aqueous system solutions is 14.23 nM, which is far below the maximum allowable amount of Al 3+ in drinking water. Moreover, the probe provided an effective method for detecting low concentrations of Al 3+ in natural water, living cells, zebrafish and plant tissues.