Colorimetric sensing of trace UO22+ by using nanogold-seeded nucleation amplification and label-free DNAzyme cleavage reaction
Colorimetric sensing of trace UO22+ by using nanogold-seeded nucleation amplification and label-free DNAzyme cleavage reaction
复制标题
使用纳米金种子成核扩增和无标记 DNAzyme 裂解反应对痕量 UO22 进行比色传感
DOI：
10.1039/c2an00039c
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发表时间：
2012-01-01
期刊：
影响因子：
4.2
通讯作者：
Jiang, Zhiliang
中科院分区：
文献类型：
--
作者：
Luo, Yanghe;Zhang, Yi;Jiang, Zhiliang
在80 ℃、pH 4.4的HAC-NaAC缓冲溶液中，纳米金颗粒（NG）对Ag（I）-没食子酸的缓慢显色反应有明显的增强作用，纳米银颗粒在460 nm处有较强的表面等离子体共振（SPR）吸收峰，而聚集态纳米金颗粒（ANG）的增强作用较弱。在460 nm处的吸光度增加值与NG浓度在3.6-72.5 ng/mL Au范围内呈线性关系。在pH 5.5的MES缓冲液中，在80 ℃下，单链底物DNA和DNAzyme杂交以形成双链DNA（dsDNA）。铀酰（UO 22+）的存在导致dsDNA的底物DNA裂解，释放出短的单链DNA，其可以吸附到NG上并保护它们免于聚集;那些未吸附的NG聚集成ANG。随着UO 22+浓度的增加，更多的短单链DNA被释放出来，更多的NG被底物单链DNA切割保护，因此有色颗粒反应和460 nm处的吸收值呈线性增加。在这些理由，0.083-0.67 nmol L-1的UO 22+可以快速检测的比色传感分析，与0.04 nmol L-1的检测限。
In pH 4.4 HAC-NaAC buffer solution at 80 degrees C, nanogold particles (NG) strongly enhanced the slow, colored reaction of Ag(I)-gallic acid to form nanosilver particles, which exhibited a strong surface plasmon resonance (SPR) absorption peak at 460 nm, but the aggregated nanogold particles (ANG) exhibited a weak enhancement. The increased absorption value at 460 nm was linear to the NG concentration in the range of 3.6-72.5 ng mL(-1) Au. In pH 5.5 MES buffer solution at 80 degrees C, single-stranded substrate DNA and DNAzyme hybridize to form double-stranded DNA (dsDNA). The presence of uranyl (UO22+) resulted in cleavage of the substrate DNA of dsDNA, releasing a short, single-stranded DNA that can be adsorbed onto the NG and protect them from aggregation; those un-adsorbed NG were aggregated to ANG. As the UO22+ concentration increased, more short, singlestranded DNA were released, and more NG were protected by the cleavage of substrate single-strand DNA, so the colored particle reaction and the absorption value at 460 nm enhanced linearly. On those grounds, 0.083-0.67 nmol L-1 UO22+ can be detected rapidly by this colorimetric sensing assay, with a detection limit of 0.04 nmol L-1.