2-(2′-Hydroxyphenyl)-4(3H)-quinazolinone derivatives based fluorescent probes for mercury(II) via an intramolecular proton transfer mechanism
2012
Zhang, Wei-Jun | Peng, Jing | Lu, Li-Min | Zhang, Jing | Zhang, Xiao-Bing
2-(2′,5′-Dihydroxy-phenyl)-4(3H)-quinazolinone (DHPQ), a new fluorescent dye that exhibits excited state intramolecular proton transfer (ESIPT) reaction and possesses good photophysical properties, is synthesised and used as fluorescent probe for detection of Hg²⁺. Mercuric ions can be detected and quantitated by measuring the fluorescent intensity decrease of the probe. The decrease of fluorescence intensity of DHPQ upon the addition of Hg²⁺ was attributed to the blocking of ESIPT reactions of DHPQ and quenching its fluorescence. The analytical performance characteristics of the proposed Hg²⁺ probe were investigated. The probe can be applied to the quantification of Hg²⁺ with a concentration range covering from 8.0 × 10⁻⁷ to 2.0 × 10⁻⁴ mol L⁻¹, with a working pH range of 5.5–6.5. It shows excellent selectivity for Hg²⁺ over other transition metal cations. The proposed method was testified for the Hg²⁺ assay in river water samples with satisfying recoveries.
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