Abasic sites can occur in DNA for different reasons, and thus the detection of this special molecular structure has turned into the focus of research. Here we have investigated the hybridization of abasic ssDNA to immobilized ssDNA probes by impedance spectroscopy. For this purpose three different abasic 25mer ssDNA (abasic site near the electrode; in the middle and near the solution) are studied in comparison to fully complementary 25mer ssDNA. For all abasic strands the surface binding can be followed concentration dependent via impedance spectroscopy; however, the concentration range and the maximum impedance change are found to be different compared to fullmatch ssDNA. Here, the position of the abasic site within the DNA strand significantly determines the signal behavior, and thus even allows a partial discrimination between the different abasic DNA strands. By investigating the binding in parallel by SPR, only slightly smaller surface concentrations are detected for the abasic strands in comparison to the fullmatch strand. This points to the formation of different DNA structures when abasic sites are contained.

由于各种原因，DNA中可能会出现无碱基位点，因此检测这种特殊的分子结构已成为研究的重点。在这里，我们通过阻抗谱研究了无碱基ssDNA与固定的ssDNA探针的杂交。为此，与完全互补的25mer ssDNA相比，研究了三种不同的无碱基25mer ssDNA（电极附近的碱基；溶液的中部和附近）。对于所有无碱基链，可以通过阻抗光谱法跟踪表面结合的浓度依赖性。但是，与完全匹配的ssDNA相比，浓度范围和最大阻抗变化是不同的。在这里，脱氧核糖核酸位点在DNA链中的位置显着决定了信号行为，因此甚至可以区分不同的无碱基DNA链。通过研究SPR平行结合，与完全匹配链相比，仅检测到无碱基链的表面浓度略小。当包含无碱基位点时，这表明形成不同的DNA结构。