Liu Qingye, Wei Yanyan, Luo Yanghe, Liang Aihui, Jiang Zhiliang
Key Laboratory of Ecology of Rare and Endangered Species and Environmental Conservation of Education Ministry, Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guangxi Normal University, Guilin 541004, China.
Key Laboratory of Ecology of Rare and Endangered Species and Environmental Conservation of Education Ministry, Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guangxi Normal University, Guilin 541004, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Jul 15;128:806-11. doi: 10.1016/j.saa.2014.03.008. Epub 2014 Mar 19.
In pH 7.2 Tris-HCl buffer solution containing 0.09 mol/L NaCl at 80°C, the single-stranded substrate DNA hybrids with the enzyme DNA to form double-stranded DNA (dsDNA). The substrate chain of dsDNA could be cracked catalytically by Pb(2+) to produce a short single-stranded DNA (ssDNA) that adsorbed on the Au(core)Ag(shell) nanoparticle (Au/AgNP) surface to form stable Au/AgNP-ssDNA conjugate to prevent aggregation by NaCl, and it combined with rhodamine 6G (RhG) to form RhG-Au/AgNP-ssDNA probe that exhibited a strong surface-enhanced resonance Raman scattering (SERRS) peak at 1510 cm(-1). With the increase of Pb(2+) concentration, the SERRS peak increased linearly due to the more RhG-Au/AgNP-ssDNA probe forming. Under the selected conditions, the increased SERRS intensity ΔI was linear to Pb(2+) concentration in the range of 5.0×10(-8)-7.0×10(-7) mol/L, with a detection limit of 7×10(-9) mol/L Pb(2+).
在80°C、含有0.09 mol/L NaCl的pH 7.2 Tris-HCl缓冲溶液中，单链底物DNA与酶DNA杂交形成双链DNA（dsDNA）。dsDNA的底物链可被Pb(2+)催化裂解产生短单链DNA（ssDNA），其吸附在金（核）银（壳）纳米颗粒（Au/AgNP）表面形成稳定的Au/AgNP-ssDNA共轭物以防止NaCl引起的聚集，并且它与罗丹明6G（RhG）结合形成RhG-Au/AgNP-ssDNA探针，该探针在1510 cm(-1)处呈现出强烈的表面增强共振拉曼散射（SERRS）峰。随着Pb(2+)浓度的增加，由于形成了更多的RhG-Au/AgNP-ssDNA探针，SERRS峰呈线性增加。在选定条件下，增加的SERRS强度ΔI与5.0×10(-8)-7.0×10(-7) mol/L范围内的Pb(2+)浓度呈线性关系，Pb(2+)的检测限为7×10(-9) mol/L。
