Search

Abstract: A Schiff base-type fluorescent chemosensor, 2,2′-bipyridyl-3,3′-bis-(N,N′-disalicylidene)-formyhydrazone has been synthesized and characterized. Among the various metal ions, only Al3+ induces the fluorescence enhancement of the formylhydrazone and results in “OFF–ON” type sensing with excellent selectivity and high sensitivity in aqueous system. The lowest detection limit for Al3+ is 0.17 μM, which is much lower than the permissible concentration of Al3+ for drinking water in China. Also, the chemosensor can be applied to the monitoring of Al3+ ion in aqueous solution with a pH span 6–8. Furthermore, fluorescence microscopic imaging also indicates that the formylhydrazone chemosensor has the potential for the detection of Al3+ in the biological environment. [Copyright &y& Elsevier]

Abstract: A new fluorescent chemosensor, sodium 2-(2-(1H-benzo[d]imidazol-2-yl)quinolin-8-yloxy)acetate (HL), based on 8-hydroxyquinoline derivative has been designed, synthesized and characterized. Once combined with Hg2+ in aqueous solution, HL displays a fluorescence quenching effect to form the compound mercury(II) 2-(2-(1H-benzo[d]imidazol-2-yl)quinolin-8-yloxy)acetate chloride (LHg), which could be fast dissociated by the addition of cyanide in this system so that “ON–OFF–ON” type fluorescence change can be achieved. Cyanide induces the revival of fluorescence of LHg and results in “OFF–ON” type sensing with high sensitivity and rapid response in 100% aqueous system. Furthermore, the fluorescence microscopic imaging also indicates that LHg is suitable for the detection of CN− in biological environment. [Copyright &y& Elsevier]