It is of great significance to monitor therapeutic antibodies in human serum to obtain the pharmacokinetic data for assessing their therapeutic efficacy at the dosage of administration. Here, based on the target-triggered proximity binding approach, as well as the catalytic hairpin assembly (CHA) and CRISPR/Cas12a cleavage dual signal amplification strategy, we describe the establishment of a highly sensitive method for detecting panitumumab, a cancer therapeutic monoclonal antibody, in diluted human serums. The two proximity probes bind the target panitumumab simultaneously to form initiation sequences for subsequent CHA for the cyclic yield of many dsDNAs, which further activate the specific trans-cleavage activity of Cas12a to digest lots of fluorescently quenched ssDNAs to restore drastically enhanced fluorescence for detecting panitumumab with a 0.62 pM detection limit. Besides, the sensing approach can selectively discriminate panitumumab against other monoclonal antibodies and realize low levels of panitumumab detection in diluted serums. Moreover, by simple replacement of the proximity recognition probes, the established method can be easily expanded for the development of versatile sensing platforms for different biomolecules in addition to antibodies.

监测人血清中的治疗性抗体以获得药代动力学数据，对评估其在给药剂量下的治疗效果具有重要意义。在这里，基于靶点触发的邻近结合方法，以及催化发夹组装 (CHA) 和 CRISPR/Cas12a 切割双信号放大策略，我们描述了一种用于检测癌症治疗单克隆抗体帕尼单抗的高灵敏度方法的建立，在稀释的人血清中。两个邻近探针同时结合目标帕尼单抗，形成后续 CHA 的起始序列，用于许多 dsDNA 的循环产率，这进一步激活了 Cas12a 的特异性反式切割活性，以消化大量荧光猝灭的 ssDNA，以恢复显着增强的荧光，用于检测 panitumumab，检测限为 0.62 pM。此外，传感方法可以选择性地将帕尼单抗与其他单克隆抗体区分开来，并实现稀释血清中帕尼单抗的低水平检测。此外，通过简单更换邻近识别探针，可以轻松扩展已建立的方法，以开发除抗体外不同生物分子的通用传感平台。