Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, School of Environment and Resource, Guangxi Normal University, Guilin 541000, China
Abstract：Under the condition of sodium citrate as stabilizer, the gold-selenium (AuSe) nano-alloy was prepared by sodium borohydride reduction procedure, and was modified by single-strand aptamer to obtain an aptamer nano-alloy probe (apta-AuSe) for Hg(Ⅱ). In pH 6.8 Na2HPO4-NaH2PO4 buffer solution and in the presence of NaCl of 33 mmol·L-1, the Apta-AuSe probe is not aggregation. The apta-AuSe interacts with Hg2+ to form stable double-strand T-Hg(Ⅱ)-T mismatches and to release AuSe nano-alloy particles from the probe. The released AuSe nano-alloy particles (20∶1) aggregated to form bigger clusters that resulted in the resonance scattering (RS) intensity (I590 nm) increasing at 590 nm. The increased intensity ΔI590 nm was proportional to the Hg2+ concentration from 1.3 to 1 466 nmol·L-1，with a detection limit of 0.74 nmol·L-1．The regress equation was ΔI590 nm=0.603ｃ+2.0. Thus, a new resonance scattering (RS) spectroscopy of apta-AuSe was applied to the analysis of trace mercury ion. This simple, rapid, selective and sensitive aptamer AuSe nano-alloy RS assay was applied to the determination of Hg2+ in wastewater, with satisfactory results.
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