Clinical Laboratory, Clinical Medical College and The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, 610500, P.R. China.
School of Bioscience and Technology, Chengdu Medical College, Chengdu, Sichuan, 610500, P.R. China.
Mikrochim Acta. 2024 Oct 15;191(11):671. doi: 10.1007/s00604-024-06749-8.
A electrochemical biosensor was designed utilizing a CRISPR Cas9n-driven DNA walker combined with gold-nanosphere-like covalent organic frameworks (COFs-AuNPs) to detect breast cancer markers (PIK3CA E545K ctDNA). The DNA walker probe is activated only in the presence of circulating tumor deoxyribonucleic acid (ctDNA), binding to a support probe to form a double strand that is then specifically cleaved by the Cas9n/sgRNA complex. This cleavage produces numerous DNA fragments for signal amplification. The COF-AuNPs as electrode materials facilitate electronic transfer and provide additional active sites for the immobilization of nucleic acid probes. This setup achieves a detection limit of 1.76 aM, demonstrating high sensitivity. Additionally, Cas9n improves the specificity of the sensor, accurately distinguishing a pair of base-mismatched sequences, and reducing the occurrence of false positives. Overall, the sensor exhibits excellent selectivity, reproducibility, and potential for early diagnosis of breast cancer.
设计了一种电化学生物传感器，利用 CRISPR Cas9n 驱动的 DNA walker 与金纳米球状类似共价有机框架（COFs-AuNPs）结合，用于检测乳腺癌标志物（PIK3CA E545K ctDNA）。只有在存在循环肿瘤脱氧核糖核酸（ctDNA）的情况下，DNA walker 探针才会被激活，与支持探针结合形成双链，然后由 Cas9n/sgRNA 复合物特异性切割。这种切割产生了许多用于信号放大的 DNA 片段。COF-AuNPs 作为电极材料，促进了电子转移，并为核酸探针的固定提供了更多的活性位点。该装置的检测限低至 1.76 aM，表现出高灵敏度。此外，Cas9n 提高了传感器的特异性，能够准确区分一对碱基错配序列，减少假阳性的发生。总的来说，该传感器表现出优异的选择性、重现性和用于乳腺癌早期诊断的潜力。
