|Label-Free and Substrate-Free Potentiometric Aptasensing Using Polycation-Sensitive Membrane Electrodes|
; Chen, Yan
; Xuewei Wang
; Wei Qin
|产权排序||[Ding, Jiawang; Chen, Yan; Wang, Xuewei; Qin, Wei] Chinese Acad Sci, Shandong Prov Key Lab Coastal Zone Environm Proc, Key Lab Coastal Zone Environm Proc, Yantai Inst Coastal Zone Res YIC,YICCAS, Yantai 264003, Shandong, Peoples R China; [Ding, Jiawang] Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China
|摘要||A potentiometric label-free and substrate-free (LFSF) aptasensing strategy which eliminates the labeling, separation, and immobilization steps is described in this paper. An aptamer binds specifically to a target molecule via reaction incubation, which could induce a change in the aptamer conformation from a random coil-like configuration to a rigid folded structure. Such a target binding-induced aptamer conformational change effectively prevents the aptamer from electrostatically interacting with the protamine binding domain. This could either shift the response curve for the potentiometric titration of the aptamer with protamine as monitored by a conventional polycation-sensitive membrane electrode or change the current-dependent potential detected by a protamine-conditioned polycation-sensitive electrode with the pulsed current-driven ion fluxes of protamine across the polymeric membrane. Using adenosine triphosphate (ATP) as a model analyte, the proposed concept offers potentiometric detection of ATP down to the submicromolar concentration range and has been applied to the determination of ATP in HeLa cells. In contrast to the current LFSF aptasensors based on optical detection, the proposed strategy allows the LFSF biosensing of aptamer/target binding events in a homogeneous solution via electrochemical transduction. It is anticipated that the proposed strategy will lay a foundation for development of potentiometric sensors for LFSF aptasensing of a variety of analytes where target binding-induced conformational changes such as the formation of folded structures and the opening of DNA hairpin loops are involved.|
|通讯作者||Qin, W (reprint author), Chinese Acad Sci, Shandong Prov Key Lab Coastal Zone Environm Proc, Key Lab Coastal Zone Environm Proc, Yantai Inst Coastal Zone Res YIC,YICCAS, Yantai 264003, Shandong, Peoples R China. email@example.com
|项目资助者||National Natural Science Foundation of China; Outstanding Youth Natural Science Foundation of Shandong Province[JQ200814]; Taishan Scholar Program of Shandong Province[TS20081159]
Jiawang Ding,Chen, Yan,Xuewei Wang,et al. Label-Free and Substrate-Free Potentiometric Aptasensing Using Polycation-Sensitive Membrane Electrodes[J]. Anal. Chem.,2012,84(4):2055-2061.
Jiawang Ding,Chen, Yan,Xuewei Wang,&Wei Qin.(2012).Label-Free and Substrate-Free Potentiometric Aptasensing Using Polycation-Sensitive Membrane Electrodes.Anal. Chem.,84(4),2055-2061.
Jiawang Ding,et al."Label-Free and Substrate-Free Potentiometric Aptasensing Using Polycation-Sensitive Membrane Electrodes".Anal. Chem. 84.4(2012):2055-2061.