Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Anal Chem. 2015 Feb 3;87(3):1861-6. doi: 10.1021/ac503914x. Epub 2015 Jan 21.
We report a method to measure DNA hybridization potentiometrically in a manner conducive to portable or hand-held biosensors. An electrolyte-gated transistor (EGT) based on poly(3-hexylthiophene) (P3HT) and an ion-gel serves as a transducer for surface hybridization of DNA. The key aspect of the design is the use of a floating-gate electrode functionalized with ssDNA whose potential is determined by both capacitive coupling with a primary, addressable gate electrode and the presence of adsorbed molecules. When DNA is hybridized at the floating gate, it offsets the primary gate voltage felt by the P3HT semiconductor; the offset is directly measurable and quantitatively related to the number density of dsDNA molecules. The presented sensing strategy can be readily adapted to other biomolecules of interest and integrated into a microfluidic system for field applications of biosensors.
我们报告了一种在有利于便携式或手持式生物传感器的方式中进行 DNA 杂交的电位测量方法。基于聚(3-己基噻吩)(P3HT)和离子凝胶的电解质门控晶体管(EGT)用作 DNA 表面杂交的传感器。该设计的关键方面是使用带有 ssDNA 的浮栅电极，其电势由与主寻址栅电极的电容耦合以及吸附分子的存在共同决定。当 DNA 在浮栅上杂交时，它会抵消 P3HT 半导体感受到的主栅极电压；这种偏移是可直接测量的，并且与 dsDNA 分子的数密度定量相关。所提出的传感策略可以很容易地应用于其他感兴趣的生物分子，并集成到微流控系统中，以实现生物传感器的现场应用。
