Thyroglobulin (Tg) is a significant biomarker for the diagnose and postoperative monitoring of differentiated thyroid cancer, and its recognition is urgent due to the rising prevalence. In this study, an ssDNA aptamer against Tg was obtained by capillary electrophoresis-systematic evolution of ligands via exponential enrichment (CE-SELEX). Under the optimized conditions, the sub-library was enriched well through two selection rounds. After high-throughput sequencing, eight candidate sequences were picked out and their affinities towards Tg were observed not in accordance with the order of their frequencies, whereas sequence homology played a significant role in binding affinity. The high-affinity sequence Seq.T-2 with a dissociation constant (K_d) of 3.18 μM was finally selected as the aptamer, and its affinity was confirmed qualitatively by gold nanoparticles colorimetric and quantitatively by thin film interferometry (K_d, 4.51 nM). Besides, molecular docking and dynamics simulation were performed for their binding sites prediction and affinity confirmation. Furthermore, the aptamer was applied for Tg detection, which delivered a detection limit of 5.0 nM as well as with good selectivity, and showed a good linear relationship within a wide range of 10 nM-6.4 μM of Tg spiked into the serum matrix. This study first reported Tg's aptamer which also exhibited the potential in real applications.

甲状腺球蛋白（Tg）是诊断和术后监测分化型甲状腺癌的重要生物标志物，并且由于流行率的上升，其认识迫在眉睫。在这项研究中，通过毛细管电泳通过指数富集（CE-SELEX）配体的系统进化，获得了针对Tg的ssDNA适体。在优化的条件下，通过两次选择回合，丰富了子图书馆。高通量测序后，挑选出八个候选序列，并观察到它们对Tg的亲和力与频率顺序不符，而序列同源性在结合亲和力中起着重要作用。具有解离常数（K _d的高亲和力序列Seq.T-2的3.18）μM最终选定为适体和其亲和力通过金纳米颗粒的比色定量由薄膜干涉（K定性确认_d，4.51纳米）。此外，进行了分子对接和动力学模拟，以预测其结合位点和亲和力。此外，将适体用于Tg检测，检测限为5.0 nM，并且具有良好的选择性，并且在掺入血清基质的10 nM-6.4μMTg的宽范围内显示出良好的线性关系。这项研究首先报道了Tg的适体，该适体在实际应用中也具有潜力。