Circulating tumor cells (CTCs), as a type of tumor, have attracted wide attention because of their characteristics of shedding from the primary tumor and spreading to other tissues and organs through peripheral blood. The circulating tumor DNA (ctDNA), the DNA released by CTCs and other tumor cells into the peripheral blood, was considered as a promising detection substance for clinical application. By utilizing the biocompatibility of red blood cells to realize the attachment of tetrahedral DNA (TDN), as well as the specific target recognition ability of TDN to enable efficient recognition of targets, a biocompatible electrochemical biosensor for effective and rapid detection of ctDNA was developed using methylene blue (MB) as the signal probe. The current signal and the logarithm of ctDNA concentration were linearly correlated in the range from 1 fM to 100 pM with the detection limit of 0.66 fM. With high specificity, the TDN-based biosensor can detect ctDNA efficiently in the real biological environment such as serum, which provided a potential opportunity for the early clinical diagnosis.

循环肿瘤细胞（CTCs）作为一种肿瘤，因其从原发肿瘤脱落并通过外周血扩散至其他组织器官的特点而受到广泛关注。循环肿瘤DNA（ctDNA）是CTCs和其他肿瘤细胞释放到外周血中的DNA，被认为是一种很有前途的临床检测物质。利用红细胞的生物相容性实现四面体DNA（TDN）的附着，以及T​​DN对靶点的特异性识别能力，实现对靶点的高效识别，研制了一种高效、快速检测ctDNA的生物相容性电化学生物传感器。亚甲蓝 (MB) 作为信号探针。电流信号与 ctDNA 浓度的对数在 1 fM 至 100 pM 范围内呈线性相关，检测限为 0.66 fM。基于TDN的生物传感器具有高特异性，可以在血清等真实生物环境中高效检测ctDNA，为临床早期诊断提供了潜在机会。