title: Optical Ion Sensing Platform Based on Potential-Modulated Release of Enzyme.
abstract: We report here on an optical ion sensing platform, in which a polymeric membrane ion-selective electrode (ISE) serves as not only a potentiometric transducer for ion activities in the sample solution but also a reference electrode for the potential-modulated release of enzyme from an iron-alginate-horseradish peroxidase (HRP) thin film modified working electrode. The ISE and working electrode are physically separated by a salt bridge. The dissolution of the HRP-embedded thin film can be triggered by the reduction of Fe3+, which is modulated by the potential response of the ISE to the target ion in the sample. The released enzyme induces the oxidation of its substrate mediated by H2O2to produce a visual color change. With this setup, an optical ion sensing platform for both cations (e.g., NH4+) and anions (e.g., Cl-) can be obtained. The proposed platform provides a general and versatile visual-sensing strategy for ions and allows optical ion sensing in colored and turbid solutions.
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China.
authors.forename: Jiawang
authors.initials: J
authors.lastname: Ding
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China.
authors.forename: Enguang
authors.initials: E
authors.lastname: Lv
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China.
authors.forename: Wei
authors.identifier: 0000-0002-9606-7730
authors.initials: W
authors.lastname: Qin
mesh_terms: D000464:Alginates / Q000737:chemistry; D000838:Anions / Q000032:analysis*; D002412:Cations / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D007501:Iron / Q000737:chemistry; D061848:Optical Imaging / Q000379:methods*
chemical_list: D000464:Alginates; D000838:Anions; D002412:Cations; D007501:Iron; D006735:Horseradish Peroxidase