基于铁氰化镍的非标记型核酸适配体电化学传感器检测凝血酶

在玻碳电极（GCE）表面首先用增敏作用的多壁碳纳米管(MWCNTs)夹心于两层电沉积的铁氰化镍（NiHCF）氧化还原电化学探针之间，然后以金纳米粒子为固定核酸适配体的载体，构建了检测凝血酶的非标记型核酸适配体生物传感器。 利用扫描电子显微镜(SEM)对MWCNTs和NiHCF的形貌进行了表征。 利用电化学阻抗谱对传感器的组装过程进行了监测，用循环伏安法（CV）和差分脉冲伏安法（DPV）对传感器的电化学行为进行了研究。 以铁氰化镍为探针的传感器对凝血酶的检测在1.0 ng/L~1.0 mg/L范围内呈良好的线性关系，相关系数为0.998，检测限为0.2 ng/L(S/N=3)。

Label-free Elechochemical Aptasensor Based on Nickel Hexacyanoferrate for the Detection of Thrombin

A label-free electrochemical aptasensor has been constructed for the electrochemical detection of thrombin. Two layers of nickel hexacyanoferrate redox probes sandwiched with multi-walled carbon nanotubes for the sensitivity enhancement were directly immobilized on the electrode surface by electrodeposition, and gold nanoparticles was used as the immobilization matrix for the aptamers. SEM was used to characterize the morphologies of multi-walled carbon nanotubes and nickel hexacyanoferrate. Electrochemical impedance spectroscopy was used to monitor the self-assembly process of aptamer biosensors. Electrochemical behaviors of aptamer biosensors were studied by cyclic voltammetry and differential pulse voltammetry. The biosensor shows a good linear range of 1.0 ng/L~1.0 mg/L(R=0.998) for the electrochemical detection of thrombin with a detection limit of 0.2 ng/L(S/N=3).