O'Connor R, Tercero N, Qiao W, Levicky R
Department of Chemical and Biological Engineering, Polytechnic Institute of New York University, Brooklyn, New York 11201, USA.
ECS Trans. 2011;35(7):99-110. doi: 10.1149/1.3571981.
Surface hybridization, in which nucleic acids from solution bind to complementary "probe" strands immobilized on a solid support, is widely used to analyze composition of nucleic acid mixtures. Most often, detection is accomplished with fluorescent techniques whose sensitivity can be extended down to individual molecules. Applications, however, benefit as much if not more from convenience, accuracy, and affordability of the diagnostic test. By eliminating the need for fluorescent labeling and more complex sample workup, label-free electrochemical assays have significant advantages provided transduction remains sufficiently sensitive for applications. To this end, we have been exploring morpholinos, which are uncharged DNA analogues, as the immobilized probe species in surface hybridization assays based on measurement of interfacial capacitance. Through comparison of experimental trends with those predicted from basic physical models, the origins of diagnostic contrast in capacitive sensing are reviewed for assays based on morpholino as well as on DNA probes.
表面杂交是指溶液中的核酸与固定在固体支持物上的互补“探针”链结合，广泛用于分析核酸混合物的组成。最常见的检测方法是荧光技术，其灵敏度可低至单个分子。然而，诊断测试的便利性、准确性和可承受性对应用的益处同样重要甚至更多。通过无需荧光标记和更复杂的样品处理，无标记电化学检测具有显著优势，前提是传感仍然对应用足够灵敏。为此，我们一直在探索吗啉代寡核苷酸，它是不带电荷的DNA类似物，作为基于界面电容测量的表面杂交检测中的固定探针物种。通过将实验趋势与基本物理模型预测的趋势进行比较，对基于吗啉代寡核苷酸以及DNA探针的电容传感诊断对比度的来源进行了综述。
