Key Laboratory for Organic Electronics and Information Displays (KLOEID) & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
College of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
ACS Appl Mater Interfaces. 2020 Oct 21;12(42):48133-48139. doi: 10.1021/acsami.0c12897. Epub 2020 Oct 1.
The state of probe DNA at the biosensing interface greatly affects the detection performance of electrochemical DNA biosensors. Herein, we constructed a target-induced hairpin-mediated biosensing interface to study the effect of probe DNA on the analytical performance of adenosine triphosphate aptamer (ATPA) and adenosine triphosphate (ATP) detection. Moreover, we also explored the electrochemical contribution of the coexisting hairpin and double-stranded DNA (dsDNA) to this sensing interface. Experimental results suggested that the molecular recognition ability and detection performance of the biosensing interface were majorly dependent on the surface density of methylene blue (MB)-labeled probe hairpin DNA and partly affected by the spatial state of the formed dsDNA. When the surface density of hairpin DNA was moderate (5.72 pmol cm), this sensing interface determined as low as 0.74 fM ATPA and 5.04 pM ATP with high selectivity and excellent regeneration, respectively. Furthermore, we calculated that the formed dsDNA had a 31.87% contribution in the total electrochemical signal for 10 pM ATPA detection. Based on the above results, we designed an XOR logic gate based on the biosensing interface for ATPA and ATP detection.
在生物传感界面上，探针 DNA 的状态极大地影响电化学 DNA 生物传感器的检测性能。在此，我们构建了一种基于目标诱导发夹介导的生物传感界面，以研究探针 DNA 对腺苷三磷酸适配体（ATPA）和腺苷三磷酸（ATP）检测分析性能的影响。此外，我们还探索了发夹和双链 DNA（dsDNA）的电化学贡献对这种传感界面的影响。实验结果表明，生物传感界面的分子识别能力和检测性能主要取决于亚甲蓝（MB）标记的探针发夹 DNA 的表面密度，部分受形成的 dsDNA 的空间状态影响。当发夹 DNA 的表面密度适中（5.72 pmol cm）时，该传感界面对 0.74 fM 的 ATPA 和 5.04 pM 的 ATP 具有高选择性和出色的再生能力，分别具有低至 0.74 fM 的检测限和 5.04 pM 的检测限。此外，我们计算出形成的 dsDNA 对 10 pM ATPA 检测的总电化学信号有 31.87%的贡献。基于上述结果，我们设计了基于生物传感界面的 ATPA 和 ATP 检测的异或逻辑门。
