Preparation of Aptamer Responsive DNA Functionalized Hydrogels for the Sensitive Detection of α-Fetoprotein Using SERS Method
Preparation of Aptamer Responsive DNA Functionalized Hydrogels for the Sensitive Detection of α-Fetoprotein Using SERS Method
复制标题
适配体响应 DNA 功能化水凝胶的制备用于 SERS 法灵敏检测甲胎蛋白
DOI：
10.1021/acs.bioconjchem.9b00874
复制
发表时间：
2020-03-01
影响因子：
4.7
通讯作者：
Zhuang, Xiumei
中科院分区：
文献类型：
--
作者：
Wang, Qi;Hu, Yongjun;Zhuang, Xiumei
肝细胞癌作为三大癌症之一，因其病死率高、医疗费用高、治疗方法有限而受到越来越多的关注。因此，建立一种快速、准确、灵敏的检测肝癌特异性标志物甲胎蛋白(AFP)的方法，对肿瘤的诊断和治疗具有重要意义。在这里，我们构建了一种新型的结合靶响应DNA水凝胶的SERS生物传感平台，用于AFP的灵敏检测。DNA水凝胶中的连接链是一种能特异性识别AFP的适配子，能准确控制水凝胶中免疫球蛋白G(Ig G)的释放。在AFP存在下，水凝胶解缠，释放出免疫球蛋白。随后，SERS探针和生物功能磁珠通过形成三明治状结构捕获释放的免疫球蛋白，导致磁分离后上清液中的拉曼标记信号减弱。由于SERS生物传感器的超高灵敏度，该方法具有较宽的检测线性范围(50pg/m L~0.5µg/m L)，检测下限可达50pg/m L。此外，DNA水凝胶中的连接链序列可以被特异地编码成对其他癌症标记物有反应的新适配子。这种简便、廉价的检测方法为肿瘤标志物的检测提供了一种新的策略。
Hepatocellular carcinoma (HCC), which is one of the three major cancers, has attracted growing attention due to its high mortality, health care cost, and circumscribed therapeutic methods. Hence, the development of a fast, accurate, and flexible method to detect a-fetoprotein (AFP), the specific marker of HCC, is significant for diagnosis and treatment of cancer. Here, we constructed a novel SERS biosensing platform combining the target-responsive DNA hydrogel for the sensitive detection of AFP. The linker strand in DNA hydrogel is an aptamer that can specifically recognize AFP and accurately control the release of immunoglobulin G (IgG) encapsulated in hydrogel. In the presence of AFP, the hydrogels were disentangled and the IgG was released. Thereafter, the released IgG was captured by SERS probes and biofunctional magnetic beads through formation of sandwich-like structures, resulting in the signal of Raman tags decreasing in the supernatant after magnetic separation. Due to the ultrahigh sensitivity of the SERS biosensor, the proposed method has a wide detection linear range (50 pg/mL to 0.5 mu g/mL) and a detection limit down to 50 pg/mL. Moreover, the sequence of the linker strand in the DNA hydrogel can be specifically encoded into a new aptamer that responds to other cancer markers. This convenient and inexpensive detection method provides a new strategy for the detection of tumor markers.