College of Chemistry and Chemical Engineering, Shandong Sino Japanese Center for Collaborative Research of Carbon Nanomaterials, Qingdao University, Qingdao, 266071, China.
Zibo Normal College, Zibo, 255200, Shandong, China.
Anal Chim Acta. 2020 Jan 15;1094:18-25. doi: 10.1016/j.aca.2019.10.003. Epub 2019 Oct 9.
A competitive electrochemical aptasensor based on a cDNA-ferrocene/MXene probe is used to detect the breast cancer marker Mucin1 (MUC1). MXene (TiC) nanosheets with excellent electrical conductivity and large specific surface area are selected as carriers for aptamer probes. The ferrocene-labeled complementary DNA (cDNA-Fc) is first bound on the surface of MXene to form a cDNA-Fc/MXene probe. Then, the MUC1 aptamer is fixed to the electrode by Au-S bonds. The sensing electrode is named Apt/Au/GCE. After the probe is complementary to the aptamer, a cDNA-Fc/MXene/Apt/Au/GCE aptasensor is fabricated. When the aptasensor is used for detection of MUC1, a competitive process happens between the cDNA-ferrocene/MXene probe and MUC1, which makes cDNA-Fc/MXene probe detach from the sensing electrode, resulting in a decrease in electrical signal. The difference in the corresponding peak current before and after the competition can be used to indicate the quantitative change in bound MUC1. The proposed competitive electrochemical aptasensor gives a wide linear range of 1.0 pM-10 μM and a low detection limit of 0.33 pM (S/N = 3), which is promising for clinical diagnosis.
基于 cDNA-二茂铁/MXene 探针的竞争性电化学适体传感器用于检测乳腺癌标志物粘蛋白 1（MUC1）。选择具有优异导电性和大比表面积的 MXene（TiC）纳米片作为适体探针的载体。首先将标记有二茂铁的互补 DNA（cDNA-Fc）结合到 MXene 表面上，形成 cDNA-Fc/MXene 探针。然后，通过 Au-S 键将 MUC1 适体固定在电极上。传感电极被命名为 Apt/Au/GCE。当探针与适体互补时，制备出 cDNA-Fc/MXene/Apt/Au/GCE 适体传感器。当适体传感器用于检测 MUC1 时，cDNA-二茂铁/MXene 探针与 MUC1 之间发生竞争过程，导致 cDNA-Fc/MXene 探针从传感电极上脱离，从而导致电信号下降。竞争前后相应峰电流的差异可用于指示结合的 MUC1 的定量变化。所提出的竞争性电化学适体传感器具有 1.0 pM-10 μM 的宽线性范围和 0.33 pM 的低检测限（S/N=3），有望用于临床诊断。
