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Detection of Hg in complex natural environmental conditions is extremely challenging, and no entirely successful methods currently exist. Here we report an easy-to-prepare fluorescent sensor B3 with 2-aminophenol as Hg receptor, which exhibits selective fluorescence enhancement toward Hg over other metal ions. Especially, the fluorescence enhancement was unaffected by anions and cations existing in environment and organism. Moreover, B3 can detect Hg in sulphide-rich environments without cysteine, S or EDTA altering the fluorescence intensity. Consequently, B3 is capable of distinguishing between safe and toxic levels of Hg in more complicated natural water systems with detection limit ≤2 ppb. [ABSTRACT FROM AUTHOR]

A new fluorescent sensor (1) for Pb2+ containing a 1,4-dicyano-2,5-bis(styryl)benzene fluorophore and 2-( N, N′-bis(carboxylmethyl))amino-1-carboxylmethoxylbenzene as receptor has been synthesized. The sensor selectively responds to Pb2+ in the aqueous environment, and brings about similar and significant changes in one- and two-photon excited emission spectra: λ max red-shift from 460 (519) to 590 nm. The selective response is pH-independent in a large physiological pH range, and two-photon action cross section ( ϕδ) is 51 GM (1 GM = 1×10−50 cm4·s·photon−1·molecule−1) at 740 nm. [ABSTRACT FROM AUTHOR]