Naphthalene based highly selective OFF-ON-OFF type fluorescent probe for Al3+ and NO2 - ions for living cell imaging at physiological pH

A naphthalene based fluorescent probe, 1-((Z)-(naphthalene-4-ylimino) methyl) naphthalene-2-ol (L) has been synthesized by condensing 1-naphthyl amine with 2-hydroxy naphthaldehyde. The structure of L has been established by single crystal X-ray structure. It selectively binds Al3+ with a binding constant (K-a) of 1.83 x 10(5) M (1/2) and detection limit of 1.0 x 10 (7) M. Moreover, [L-Al3+] complex can detect NO2 ion as low as 5.7 x 10 (8) M. Binding of L to Al3+ and [L-Al3+] complex to NO2 ion has been established by different spectroscopic studies. The probe is very effective for detection of intracellular Al3+ through fluorescence microscopic imaging. (C) 2012 Elsevier B.V. All rights reserved.