Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China.
School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , China.
Anal Chem. 2019 Sep 17;91(18):11614-11619. doi: 10.1021/acs.analchem.9b01897. Epub 2019 Sep 6.
Circulating tumor cells (CTCs) are important indicators for tumor diagnosis and tumor metastasis. However, the extremely low levels of CTCs in peripheral blood challenges the precise detection of CTCs. Herein, we report DNA generated electrochemical current combined with rolling circle amplification (RCA) as well as magnetic nanospheres for highly efficient magnetic capture and ultrasensitive detection of CTCs. The antiepithelial cell adhesion molecule (EpCAM) antibody-modified magnetic nanospheres were used to capture and enrich CTCs. The following binding of an aptamer onto the CTC surface and the subsequent RCA assembled a significant amount of DNA molecules onto the electrode. The reaction of the DNA molecules with molybdate can then form redox molybdophosphate and produce an electrochemical current. Using the breast cancer cell MCF-7 as a model, the sensor displays good performances toward detection of MCF-7 that was spiked into peripheral blood. The signal amplification strategy integrated with a magnetic nanosphere platform exhibits good performance in the efficient capture and detection of CTCs, which may find wide potential in cancer diagnostics and therapeutics.
循环肿瘤细胞（CTCs）是肿瘤诊断和肿瘤转移的重要指标。然而，外周血中 CTCs 的极低水平对 CTCs 的精确检测提出了挑战。在此，我们报告了 DNA 产生的电化学电流与滚环扩增（RCA）以及磁性纳米球结合，用于高效地磁性捕获和超灵敏检测 CTCs。用抗上皮细胞黏附分子（EpCAM）抗体修饰的磁性纳米球来捕获和富集 CTCs。随后，一个适体与 CTC 表面结合，并且随后的 RCA 将大量的 DNA 分子组装到电极上。DNA 分子与钼酸盐的反应可以形成氧化还原钼磷酸盐并产生电化学电流。使用乳腺癌细胞 MCF-7 作为模型，该传感器对 MCF-7 的检测表现出良好的性能，MCF-7 被掺入外周血中。与磁性纳米球平台集成的信号放大策略在 CTCs 的高效捕获和检测方面表现出良好的性能，这可能在癌症诊断和治疗中具有广泛的应用潜力。
