Synthesis and Spectral Studies of a Novel Benzoxazole-Derived Fluorescent Probe for Hg2+

A novel turn-off fluorescent probe bearing a benzoxazole fluorophore has been synthesised and characterised. Its recognition properties towards different metal ions have been researched by spectrometry. The probe was highly selective and sensitive to Hg2+ and showed a complexation ratio towards Hg2+ of 1:1. Its fluorescence intensity varied almost linearly with the concentration of Hg2+ (1.6~8.6 μmol L−1), and the detection limit of Hg2+ was estimated to be 0.68 μmol L−1.

Time-resolved probes and oxidase-based biosensors using terbium(III)-guanosine monophosphate-mercury(II) coordination polymer nanoparticles

A novel lanthanide coordination polymer nanoparticle (LCPN)-based ternary complex was synthesized via the self-assembly of a terbium ion (Tb(3+)) with a nucleotide (GMP) and a mercury ion (Hg(2+)) in aqueous solution. The as-prepared LCPN-based ternary complex (Tb-GMP-Hg) can be applied to the development of time-resolved luminescence assays and oxidase-based biosensors.

4-(8-Quinolyl)amino-7-nitro-2,1,3-benzoxadiazole as a new colorimetric probe for rapid and visual detection of Hg2+

4-Amino-7-nitro-2,1,3-benzoxadiazole (ANBD) usually serves as a scaffold for developing fluorescent probes. In this paper, however, ANBD has been used as a chromogenic unit to design a new colorimetric probe, 4-(8-quinolyl)amino-7-nitro-2,1,3-benzoxadiazole (1), for rapid and visual detection of Hg(2+). The reaction of 1 with Hg(2+) in NaH(2)PO(4)-Na(2)HPO(4) buffer (pH 7.0) containing 70% (v/v) acetonitrile forms a 1:1 complex, accompanying a red shift of the absorption maximum from 482 nm to 557 nm and a distinct color change from orange to violet. Moreover the color reaction exhibits a high selectivity and sensitivity to Hg(2+) only, instead of other common metal ions. This behavior may be ascribed to the formation of a specific 1-Hg(2+) complex, which is supported by (1)H NMR titration experiments. The present study is not only a supplement to the detection method of Hg(2+), but also a merit to the chemistry of 4-amino-7-nitro-2,1,3-benzoxadiazole.