Determination of soluble CD44 in serum by a label-free aptamer based electrochemical impedance biosensor
Determination of soluble CD44 in serum by a label-free aptamer based electrochemical impedance biosensor
复制标题
基于无标记适配体的电化学阻抗生物传感器测定血清中可溶性CD44
作者：
Jie Zhou;Xuan Chen;Kai Cheng;Rui Yang;Mudan Lu;Lan Ming;Yu Chen;Zhenyu Lin;Daozhen Chen
CD44在恶性肿瘤的诊断和预后中是一个很有前景的生物标志物。血清CD44水平与恶性肿瘤的进展和转移密切相关。血清可溶性CD44的检测具有重要的临床意义。在这项研究中，提出了一种简单的、无标记的、基于适体的血清CD44电化学阻抗传感器。对CD44具有高亲和力的适配体通过Au-S相互作用固定在金电极上。靶CD44与固定化适配体的相互作用会使适配体发生复杂的结构变化，使[Fe(CN)6]3−/4−易于向电极表面扩散，从而导致体系阻抗降低。阻抗降低程度与CD44浓度的对数在0.1 ~ 1000 ng mL−1范围内呈良好的线性关系，检出限为0.087 ng mL−1 （S/N = 3）。所研制的生物传感器已用于血清样品中CD44的检测，取得了满意的结果。
CD44 is a promising biomarker in the diagnosis and prognosis of malignancies. The serum CD44 level is closely related to disease progression and metastasis of malignancies. It is of great clinical significance for the detection of serum soluble CD44. In this study, a facile, label-free aptamer based electrochemical impedance sensor for serum CD44 has been proposed. The aptamer showing high affinity to CD44 was immobilized on the gold electrodes through Au–S interaction. The interaction between target CD44 and the immobilized aptamer will cause a complex structure change of the aptamer, which makes the diffusion of [Fe(CN)6]3−/4− toward the electrode surface easy, thus resulting in the decrease of the impedance of the system. The decreased degree of the impedance had a good linear relationship with the logarithm of the CD44 concentration in the range of 0.1–1000 ng mL−1 with a detection limit of 0.087 ng mL−1 (S/N = 3). The developed biosensor has been applied to detect CD44 in serum samples with satisfactory results.