Electrical Engineering Department, Autonomous University of Zacatecas, Col. Centro, Av. Ramón López Velarde 801. Zacatecas, Zacatecas C.P. 98000, México.
Chemistry Department, Autonomous University of Zacatecas, Campus Siglo XXI, Edif. 6, Km 6 carr. Zacatecas-Guadalajara, Zacatecas C.P. 98160, México.
Sensors (Basel). 2019 Sep 13;19(18):3956. doi: 10.3390/s19183956.
DNA electrochemical biosensors represent a feasible alternative for the diagnosis of different pathologies. In this work, the development of an electrochemical method for Human Papillomavirus-16 (HPV-16) sensing is reported based on potential relaxation measurements related to the discharge of a complex double layer of a DNA-modified gold electrode. The method used allows us to propose an equivalent circuit (EC) for a DNA/Au electrode, which was corroborated by electrochemical impedance spectroscopy (EIS) measurement. This model differs from the Randles circuit that is commonly used in double-layer simulations. The change in the potential relaxation and associated charge transfer resistance were used for sensing the DNA hybridization by using the redox pair Fe(CN)/Fe(CN) as an electrochemical indicator. In order to determinate only the potential relaxation of the composed double layer, the faradic and double-layer current contributions were separated using a rectifier diode arrangement. A detection limit of 0.38 nM was obtained for the target HPV-16 DNA sequences. The biosensor showed a qualitative discrimination between a single-base mismatched sequence and the fully complementary HPV-16 DNA target. The results indicate that the discharge of the double-layer detection method can be used to develop an HPV DNA biosensor.
DNA 电化学生物传感器是用于不同病理诊断的可行选择。在这项工作中，报道了一种基于与金电极上 DNA 修饰的双层放电相关的电势弛豫测量的人乳头瘤病毒 16（HPV-16）感测的电化学方法的开发。所使用的方法允许我们针对 DNA/Au 电极提出等效电路 (EC)，这通过电化学阻抗谱 (EIS) 测量得到了证实。该模型与通常用于双层模拟的 Randles 电路不同。通过使用氧化还原对 Fe(CN)/Fe(CN)作为电化学指示剂来感测 DNA 杂交，电势弛豫和相关的电荷转移电阻的变化被用于感测。为了仅确定组成双层的电势弛豫，使用整流二极管布置分离了法拉第和双层电流贡献。对于目标 HPV-16 DNA 序列，获得了 0.38 nM 的检测限。该生物传感器能够对单碱基错配序列和完全互补的 HPV-16 DNA 靶标进行定性区分。结果表明，双层检测方法的放电可用于开发 HPV DNA 生物传感器。
