Exploration and application of a highly sensitive bis(salamo)-based fluorescent sensor for B 4 O 7 2? in water-containing systems and living cells

摘要

A highly selective fluorescent sensor H₄L based on a bis(salamo)-type compound with two N₂O₂ chelating moieties as ionophore was successfully developed. Sensor H₄L was found to have excellent selectivity for B₄O₇2? over many other anions (Br?, CI?, CN?, CO₃2?, HCO₃?, H₂PO₄?, HSO₄?, NO₃?, OAc?, S₂O₃?, SCN?, SO₄2?, Hcy (homocysteine) and H₂O₂), and it exhibited an approximately 150-fold enhancement of the fluorescence response to B₄O₇2? in Tris-HCl buffer (DMF/H₂O?=?9:1, v / v , pH?=?7) solutions. Significantly, its fluorescence intensity was enhanced in a linear fashion with increasing concentrations of B₄O₇2?. The detection limit of sensor H₄L towards B₄O₇2? was 8.61?×?10?7 M. The test strips could conveniently, efficiently and simply detect B₄O₇2? ions in Tris-HCl buffer (DMF/H₂O?=?9:1, v / v , pH?=?7) solutions. Furthermore, sensor H₄L showed excellent membrane permeability in living cells, and it was successfully used to monitor intracellular B₄O₇2? by confocal luminescence imaging.