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Abstract: In the paper, a novel mutli-wavelength emissive aluminium ion chemosensor based on 3-[1′-(2′-hydroxy-α-methylbenzylidene-imino)]-2-(p-N,N-dimethyl aminophenyl)-1,2-dihydroquinazolin-4-(3H)-one is designed and synthesized. According to the fluorescence behavior toward several metal ions, it shows high selectivity to Al3+ over other commonly coexistent metal ions (Na+, Mg2+, Co2+, Ni2+, Cu2+, Fe3+, Cr3+, Hg2+, Zn2+, Cd2+) in aqueous environment (pH 7.40). Meanwhile the binding constant between Al3+ and chemosensor achieves 3.92×106 M−1 in aqueous media. Moreover, according to the Job plot, 1:1 stoichiometry between Al3+ and the sensor was deduced in aqueous media (pH 7.4). The good selectivity and sensitivity in aqueous media effectively enhance the application value of the chemosensor for Al3+. [Copyright &y& Elsevier]

8-hydroxyquinoline-5-carbaldehyde-(benzotriazol-1′-acetyl)hydrazone1was synthesized and found to show sensitivity and selectivity to Mg2+. Compared to other metal ions, the fluorescence intensity of1increased 65-fold upon addition of Mg2+with a low detection limit of 2.4 ppb in acetonitrile. [ABSTRACT FROM AUTHOR]

A Schiff-base fluorescent sensor, 7-methoxychromone-3-carbaldehyde-(3′,4′-dimethyl)pyrrole hydrazone (MCPH), was synthesized. The new sensor showed high selectivity for Al3+ over other metal ions examined in acetonitrile. Upon binding Al3+, a significant fluorescence enhancement with a turn-on ratio over 101-fold was triggered. The detection limit of MCPH for Al3+ was 2.5 × 10−7 mol L−1. [ABSTRACT FROM AUTHOR]

Abstract: Iron oxide magnetic nanoparticles were covalently modified by a fluorescent 8-aminoquinoline derivative and formed an optical sensor to be used as a highly sensitive and selective Zn2+ ions fluorescent nanosensor in aqueous solution at pH 7.0. The nanosensor was sufficiently characterized by physicochemical methods. The sensor can detect Zn2+ ions in aqueous solution with a submicromolar sensitivity of 0.1μM, and the interfering metal ions cannot influence its selectivity. MTT assay experiments indicated that the sensor showed no apparent cytotoxicity. [Copyright &y& Elsevier]

In order to obtain high selectivity and high quenching efficiency fluorescent sensors for 2,4,6-trinitrophenol ( TNP ), a ligand [5-(diethylamino)-2-((quinolin-8-ylimino)methyl)phenol hydrochloride, H 2 LCl ] was obtained by the condensation of 4-(diethylamino)salicylaldehyde and 8-aminoquinoline in the present of HCl; and two Zn(II) complexes, namely [Zn 2 ( μ 2 -L)( μ 2 -CH 3 COO) 2 Cl] ( 1 ) and [Zn 2 ( μ 2 -L) 2 (NO 3 ) 2 ] ( 2 ), were also prepared via the reaction of H 2 LCl with Zn(AcO) 2 ·2H 2 O or Zn(NO 3 ) 2 ·6H 2 O. 1 (in chloroform) and 2 (in methanol) showed strong emission centered at 498 nm and 540 nm respectively, and both of them displayed superior selectivity and high quenching efficiency to TNP among other nitroaromatics and analogues (i.e., 2,4,6-trinitrotoluene, phenol, nitrobenzene, o -nitrophenol, p -nitrotoluene, m -nitrotoluene, and salicylic acid). 6 equ. of TNP made 92% fluorescence quenching of 1 , and 8 equ. of TNP induced 85% quenching of 2 . The detection limits for TNP were found to be 0.154 ppm of 1 and 1.01 ppm of 2 . [ABSTRACT FROM AUTHOR]