CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China.
University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
ACS Sens. 2024 Nov 22;9(11):6157-6166. doi: 10.1021/acssensors.4c02004. Epub 2024 Oct 23.
Nowadays, using a potentiometric ion sensor to achieve detection of biological analytes is still a big challenge, since these analytes usually do not yield a measurable ion signal. To address this challenge, a simple and robust potentiometric sensing protocol based on a delayed Nernstian response is proposed for the label-free detection of biological analytes. The proposed sensor platform is composed of two layers: the surface recognition layer and the indicator-ion-selective electrode (ISE) membrane layer. It is based on a surface blocking mechanism in which the surface recognition interactions between the surface recognition element and the target can impede the diffusion of the indicator ion from the aqueous phase to the sensing membrane phase to reach the final Nernstian-response equilibrium, thus resulting in a delayed potential change. Such a potential change could be used to measure the concentration of a biological target in the sample. Thus, a sensing system was designed by using phage MS2, its host bacterium ATCC 15597(abbreviated as H), and a solid-contact butyrylcholine ISE as a surface recognition element, a target, and an indicator electrode, respectively. This new concept offers a simple, sensitive, and extremely selective potentiometric method for detection of H with a detection limit of 100 CFU mL. It can be expected that the present approach may pave the way to using ISEs to detect various important nonionic biological targets in clinical and environmental applications.
如今，使用电位离子传感器来实现对生物分析物的检测仍然是一个巨大的挑战，因为这些分析物通常不会产生可测量的离子信号。为了解决这个挑战，本文提出了一种简单而稳健的基于延迟能斯特响应的电位传感协议，用于生物分析物的无标记检测。所提出的传感器平台由两层组成：表面识别层和指示剂离子选择性电极（ISE）膜层。它基于表面阻断机制，其中表面识别元件与目标之间的表面识别相互作用会阻碍指示剂离子从水相扩散到传感膜相以达到最终的能斯特响应平衡，从而导致延迟的电位变化。这种电位变化可用于测量样品中生物靶标的浓度。因此，设计了一个传感系统，分别使用噬菌体 MS2、其宿主菌 ATCC 15597（简写为 H）和固体接触丁酰胆碱 ISE 作为表面识别元件、目标和指示剂电极。该新概念提供了一种简单、灵敏和极其选择性的电位检测方法，用于检测 H，检测限为 100CFU mL。可以预期，本方法可能为使用 ISE 检测临床和环境应用中各种重要的非离子生物靶标铺平道路。
