设计了基于分支DNA的电化学生物传感器以灵敏地检测特定核酸。在这个平台上,具有三个粘性末端的新型分支DNA可用作生物传感器,以灵敏和特异性地检测核酸。同时,我们还使用分支DNA修饰的AuNP作为信号放大器,以进一步提高灵敏度。分支DNA传感器,靶DNA,和DNA修饰的AuNP形成夹心结构以产生用于靶DNA检测的电子信号。该反应主要涉及DNA杂交而没有庞大的热循环仪和酶。我们证明了杂交反应在不同条件下容易发生,例如NaCl浓度,反应时间,pH值,和温度,除了pH低于4。检测限可以低至0.09pM(S/N=3),具有出色的特异性和选择性。峰电流与靶DNA浓度的对数(0.10pM至10nM)之间存在相关曲线关系。相关系数达到0.987。电化学平台使得分支DNA纳米结构能够确定用于疾病诊断的核酸。
A branched DNA-based electrochemical biosensor was designed to sensitively detect specific nucleic acids. On this platform, novel a branched DNA with three sticky ends could be used as a biosensor to sensitively and specifically detect nucleic acids. Meanwhile, we also employed branched DNA-modified AuNPs as a signal amplifier to further improve the sensitivity. Branched DNA sensors, target DNA, and DNA-modified AuNPs formed a sandwich structure to produce an electronic signal for target DNA detection. The reaction primarily involved DNA hybridization without bulky thermal cyclers and enzymes. We proved that the hybridization reaction easily occurred under different conditions, such as the NaCl concentration, reaction time, pH, and temperature, except for a pH lower than 4. The limit of detection could go as low as 0.09 pM (S/N = 3) with excellent specificity and selectivity. There was a correlation curve relationship between the peak current and the logarithm of the target DNA concentration (0.10 pM to 10 nM). The correlation coefficient reached 0.987. The electrochemical platform enables a branched DNA nanostructure to determine nucleic acids for disease diagnosis.