Assessment of Deoxyribonuclease Activity Using DNA Molecules Immobilized Between Microelectrodes
Assessment of Deoxyribonuclease Activity Using DNA Molecules Immobilized Between Microelectrodes
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DOI：
10.1007/s11664-020-08596-8
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发表时间：
2021-02-01
影响因子：
2.1
通讯作者：
Saito, Yoji
中科院分区：
文献类型：
--
作者：
Himuro, Takahiro;Saito, Yoji
血清脱氧核糖核酸酶I（DNase I）可作为急性心肌梗死及其他疾病治疗监测的功能性生物标志物。在这里，我们证明了DNA分子的电特性可以用来监测酶的活性。基于电化学阻抗技术，设计了一种检测DNA酶I活性的免标记DNA生物传感器。将多个λ噬菌体DNA分子固定在聚二甲基硅氧烷储器中的两个电极之间。从EIS测量估计的等效电路用于计算电极之间的DNA分子的阻抗。然后，在DNA酶I切割DNA后，通过测量阻抗的增加来实现DNA酶检测。这通过阻抗增加比来评估，阻抗增加比定义为R-after/R-before（其中R-before和R-after分别表示在DNA酶I处理之前和之后电极固定的DNA分子之间的电阻）。在用浓度为10（-2）单位/μ L的DNA酶I处理后，获得了约3.3倍的可再现的阻抗增加比，标准偏差小于20%。当引入不同浓度的DNA酶溶液时，我们成功地获得了DNA酶浓度与阻抗增加率之间的确定的相关性，范围为10（-4）单位/μ L至10（-1）单位/μ L。
Serum deoxyribonuclease I (DNase I) can serve as a functional biomarker for the therapeutic monitoring of acute myocardial infarction and other diseases. Here, we demonstrate that the electrical properties of DNA molecules can be exploited to monitor enzymatic activity. A label-free DNA biosensor for the detection of DNase I activity was devised based on electrochemical impedance spectroscopy (EIS). Multiple lambda phage DNA molecules were immobilized between two electrodes in a polydimethylsiloxane reservoir. An equivalent circuit estimated from the EIS measurement was used to calculate the impedance of DNA molecules between the electrodes. DNase detection was then achieved by measuring the increase in impedance, after DNA cleavage by DNase I. This was assessed by the impedance-increase ratio, defined as R-after/R-before (where R-before and R-after represent the resistance between the electrode-immobilized DNA molecules before and after DNase I treatment, respectively). After treatment with DNase I at a concentration 10(-2) unit/mu L, a reproducible impedance-increase ratio of approximately 3.3 times was obtained, with a standard deviation of less than 20%. When DNase solutions of various concentrations were introduced, we succeeded in obtaining a definite correlation between DNase concentration and impedance-increase rate, within the range of 10(-4) unit/mu L to 10(-1) unit/mu L.