基于四链体核酸构型转变快速检测Pb^(2+)的比色传感器

A colorimetric biosensor based on the G-quadruplex conformation transition for rapid detection of lead ions

基于特定盐浓度条件下金纳米颗粒的聚集程度受附着于金纳米表面DNA浓度的影响,以及铅离子(Pb^(2+))能引起特定DNA构象变化而使其不能附着在纳米金表面的特点,设计了一种新型的Pb^(2+)生物传感器。当Pb^(2+)浓度在0.05~10 nmol/L的范围内时,体系的吸光度A712/A520随Pb^(2+)浓度对数值的变化而呈现线性关系,线性常数为0.994,检出限为0.03 nmol/L。在实际样品检测中,其回收率在98.6%~106.0%之间。

A new method for detection of Pb^（2＋）were designed in this paper based on the different aggregation degree of gold nanoparticles（ Au NPs） depending on the concentration of Pb^（2＋）under the conditions of free state of DNA on Au NP surface and a certain of Na Cl in solution. The specific DNA,which can combine with the Pb^（2＋）to prevent the absorption of Au NPs,was formed the G-quadruplex under the action of Pb^（2＋）. The new sensor was highly sensitive. A good linear relationship was obtained between the Pb^（2＋）concentration in the range of 0. 05 ~10 nmol / L and the detection limit was 0. 03 nmol / L. In real samples,recoveries were measured between 98. 6%~ 106. 0%.