Lai Rebecca Y, Seferos Dwight S, Heeger Alan J, Bazan Guillermo C, Plaxco Kevin W
Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
Langmuir. 2006 Dec 5;22(25):10796-800. doi: 10.1021/la0611817.
We have characterized the solution-phase and dry storage stability of electrochemical E-DNA sensors fabricated using mixed self-assembled monolayers (SAMs) composed of 6- or 11-carbon (C6 and C11, respectively) alpha,omega-thiol alcohols and the analogous C6- or C11-thiol-terminated stem-loop DNA probe. We find that the solution-phase and dry storage stability of C6-based E-DNA sensors are limited and poorly reproducible. The use of stabilizing agents bovine serum albumin plus either glucose or trehalose significantly improves the dry storage shelf life of such sensors: when using these preservatives, we observe only 7-9% sensor degradation after 1 month of storage in air at room temperature. In comparison, the stability of C11-based E-DNA sensors is significantly greater than that of the C6-based sensors; we observe only minor (5-8%) loss of signal upon storing these sensors for a week under ambient solution conditions or for more than a month in air in the presence of preservatives. Moreover, whereas the electron-transfer rate through C11 SAMs is slower than that observed for C6 SAMs, it is rapid enough to support good sensor performance. It thus appears that C11 SAMs provide a reasonable compromise between electron-transfer efficiency and sensor stability and are well suited for use in electronic DNA-sensing applications.
我们已经表征了使用由6碳或11碳（分别为C6和C11）的α,ω-硫醇醇以及类似的C6或C11硫醇末端茎环DNA探针组成的混合自组装单分子层（SAMs）制备的电化学E-DNA传感器在溶液相和干燥储存条件下的稳定性。我们发现基于C6的E-DNA传感器在溶液相和干燥储存条件下的稳定性有限且重现性差。使用稳定剂牛血清白蛋白加葡萄糖或海藻糖可显著提高此类传感器的干燥储存保质期：使用这些防腐剂时，我们观察到在室温空气中储存1个月后传感器仅降解7-9%。相比之下，基于C11的E-DNA传感器的稳定性明显高于基于C6的传感器；在环境溶液条件下将这些传感器储存一周或在有防腐剂的空气中储存一个多月后，我们仅观察到信号有轻微（5-8%）损失。此外，虽然通过C11 SAMs的电子转移速率比C6 SAMs慢，但它足够快以支持良好的传感器性能。因此，C11 SAMs似乎在电子转移效率和传感器稳定性之间提供了合理的折衷，非常适合用于电子DNA传感应用。
