A water soluble Al super(3+) selective colorimetric and fluorescent turn-on chemosensor and its application in living cell imaging

An efficient water soluble fluorescent Al super(3+) receptor, 1-[[(2-furanylmethyl)imino]methyl]-2-naphthol(1-H) was synthesized and characterized by physico-chemical and spectroscopic tools along with single crystal X-ray crystallography. High selectivity and affinity of 1-H towards Al super(3+) in HEPES buffer (DMSO/water: 1/100) of pH 7.4 at 25 degree C showed it to be suitable for detection of intracellular Al super(3+) by fluorescence microscopy. Metal ions, viz.alkali (Na super(+), K super(+)), alkaline earth (Mg super(2+), Ca super(2+)), and transition-metal ions (Ni super(2+), Zn super(2+), Cd super(2+), Co super(2+), Cu super(2+), Fe super(3+), Cr super(3+/6+), Hg super(2+)) and Pb super(2+), Ag super(+) did not interfere. The lowest detection limit for Al super(3+) was calculated to be 6.03 10 super(-7) M in 100 mM HEPES buffer (DMSO/water: 1/100). Theoretical calculations have also been included in support of the configuration of the probe-aluminium complex.