title: Bare conical nanopore embedded in polymer membrane for Cr(III) sensing.
abstract: In this article, we propose a nanopore-based approach to detect metal ions without any external functionalization. In detection of the biologically and environmentally relevant Cr(3+) ion as a prototypical example to prove our strategy, both selectivity and sensitivity were individually achieved. In contrast to mainstream research based on receptor-functionalized nanopores, we report a method for easy regeneration of the nanopore surface that allows elimination of the tedious functionalization steps. Besides, with the assistance of a strong chelator (EDTA), the asymmetric nanopore becomes highly resistant to the interference of the metal-ions matrix, and shows significant specificity towards Cr(3+). The detection limit of this sensor was 16 nM (signal-to-noise ratio=3), which was comparable to reported values. By virtue of the reusability of the polymer surface, metal ion sensors based on asymmetric nanopores can be applied universally in combination with chelators sensitive to specific metal ions.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China; National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, China.
authors.forename: Qingfeng
authors.initials: Q
authors.lastname: Zhai
authors.affiliation: National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, China. Electronic address: jiahai_wang@sdu.edu.cn.
authors.forename: Jiahai
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China. Electronic address: sdjndxwq@163.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D002412:Cations / Q000032:analysis; D002614:Chelating Agents / Q000737:chemistry; D002857:Chromium / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis*; D004492:Edetic Acid / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D060106:Lakes / Q000032:analysis*; D057230:Limit of Detection; D058608:Nanopores / Q000648:ultrastructure; D059629:Signal-To-Noise Ratio
chemical_list: D002412:Cations; D002614:Chelating Agents; D060766:Drinking Water; D002857:Chromium; D004492:Edetic Acid
keywords: Asymmetric nanopore; Chromium ion; Ion current rectification; Sensor