Department of Chemistry and Biochemistry, Center for Polymers and Organic Solids, University of California, Santa Barbara, CA 93106, USA.
Proc Natl Acad Sci U S A. 2010 Jun 15;107(24):10837-41. doi: 10.1073/pnas.1005632107. Epub 2010 Jun 1.
We have demonstrated a novel sensing strategy employing single-stranded probe DNA, unmodified gold nanoparticles, and a positively charged, water-soluble conjugated polyelectrolyte to detect a broad range of targets including nucleic acid (DNA) sequences, proteins, small molecules, and inorganic ions. This nearly "universal" biosensor approach is based on the observation that, while the conjugated polyelectrolyte specifically inhibits the ability of single-stranded DNA to prevent the aggregation of gold-nanoparticles, no such inhibition is observed with double-stranded or otherwise "folded" DNA structures. Colorimetric assays employing this mechanism for the detection of hybridization are sensitive and convenient--picomolar concentrations of target DNA are readily detected with the naked eye, and the sensor works even when challenged with complex sample matrices such as blood serum. Likewise, by employing the binding-induced folding or association of aptamers we have generalized the approach to the specific and convenient detection of proteins, small molecules, and inorganic ions. Finally, this new biosensor approach is quite straightforward and can be completed in minutes without significant equipment or training overhead.
我们已经展示了一种新颖的传感策略，该策略采用单链探针 DNA、未经修饰的金纳米粒子和带正电荷的水溶性共轭聚合物电解质，以检测包括核酸（DNA）序列、蛋白质、小分子和无机离子在内的广泛目标。这种几乎“通用”的生物传感器方法基于以下观察结果：虽然共轭聚合物电解质特异性地抑制单链 DNA 阻止金纳米粒子聚集的能力，但双链或其他“折叠”的 DNA 结构则不会观察到这种抑制。这种机制用于检测杂交的比色测定法灵敏且方便——可以用肉眼轻松检测出皮摩尔浓度的目标 DNA，即使在血清等复杂的样本基质中也能发挥作用。同样，通过采用适配体的结合诱导折叠或缔合，我们将该方法推广到蛋白质、小分子和无机离子的特异性和方便检测。最后，这种新的生物传感器方法非常简单，可以在没有重大设备或培训开销的情况下在几分钟内完成。
