基于DNAzyme与铀特异性反应的共振光散射法检测铀

Determination of uranyl based on uranyl specific DNAzyme by a resonance light scattering technique

建立了基于铀特异性DNA酶-Au NPs检测UO2^2＋的共振光散射新方法。在p H 4.5的10 mmol/L MES缓冲溶液中,铀特异性DNA酶在铀作为辅助因子的条件下发生自身断链反应,释放出ss DNA,吸附在Au NPs表面,阻止Au NPs在高浓度盐下聚集,使体系的共振光散射强度降低。在2.08×10^-9-2.00×10^-8mol/L范围内,散射光强度的改变值与UO2^2＋浓度呈良好线性关系,回归方程为ΔI=59.45＋14761 c（μmol/L）,r=0.9852,检出限为6.23×10^-10mol/L,加标回收率为95.0%-106.5%,相对标准偏差为（RSD）1.9%-9.1%,方法成功用于实际样品检测。

A novel resonance light scattering （RLS） method has been developed based on a uranyl （UO2^2＋ ） specific DNAzyme and gold nanoparticles （AuNPs）. In this strategy, the cleavage of substrate by DNAzyme in the presence of UO2^2＋ resulted in releasing a single stranded DNA （ssDNA） that could be adsorbed on AuNPs and protected them from aggregation, leading to the change of RLS intensity. The AI signal linearly correlated with the concentration of UO2^2＋ over the range of 2. 08 × 10^-9 - 2.00 × 10^-8 mol/L with a limit of detection of 6.23 × 10^-10mol/L. The spiked recoveries were 95.0% - 106.5%. RSDs were 1.9% -9. 1% （n = 6） ,The proposed method was simple and rapid with high selectivity, and had been successfully used for the determination of trace uranium in real samples with satisfactory results.