1
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Zhao J, Ding J, Luan F, Qin W. Chronopotentiometric sensors for antimicrobial peptide-based biosensing of Staphylococcus aureus. Mikrochim Acta 2024; 191:356. [PMID: 38811412 DOI: 10.1007/s00604-024-06410-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 05/04/2024] [Indexed: 05/31/2024]
Abstract
Charged antimicrobial peptides can be used for direct potentiometric biosensing, but have never been explored. We report here a galvanostatically-controlled potentiometric sensor for antimicrobial peptide-based biosensing. Solid-state pulsed galvanostatic sensors that showed excellent stability under continuous galvanostatic polarization were prepared by utilizing reduced graphene oxide/poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (rGO/PEDOT: PSS) as a solid contact. More importantly, the chronopotentiometric sensor can be made sensitive to antimicrobial peptides with intrinsic charge on demand via a current pulse. In this study, a positively charged antimicrobial peptide that can bind to Staphylococcus aureus with high affinity and good selectivity was designed as a model. Two arginine residues with positive charges were linked to the C-terminal of the peptide sequence to increase its potentiometric responses on the electrode. The bacteria binding-induced charge or charge density change of the antimicrobial peptide enables the direct chronopotentiometric detection of the target. Under the optimized conditions, the concentration of Staphylococcus aureus can be determined in the linear range 10-1.0 × 105 CFU mL-1 with a detection limit of 10 CFU mL-1. It is anticipated that such a chronopotentiometric sensing platform is readily adaptable to detect other bacteria by choosing the peptides.
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Affiliation(s)
- Jiarong Zhao
- College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264003, People's Republic of China
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Shandong Key Laboratory of Coastal Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), YICCAS, Yantai, 264003, Shandong, People's Republic of China
| | - Jiawang Ding
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Shandong Key Laboratory of Coastal Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), YICCAS, Yantai, 264003, Shandong, People's Republic of China.
| | - Feng Luan
- College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264003, People's Republic of China
| | - Wei Qin
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Shandong Key Laboratory of Coastal Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), YICCAS, Yantai, 264003, Shandong, People's Republic of China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, 266237, Shandong, People's Republic of China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, Shandong, People's Republic of China
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2
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Li J, Zhang W, Qin W. Trace-level chronopotentiometric detection in the presence of a high electrolyte background using thin-layer ion-selective polymeric membranes. Chem Commun (Camb) 2023; 59:14257-14260. [PMID: 37961819 DOI: 10.1039/d3cc04512a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
We propose here a pulsed galvanostatic control of a solid-contact ion-selective electrode coupled with a thin-layer ion-exchanger free membrane, which allows chronopotentiometric trace-level ion detection with a high-interfering background in a rapid and reversible way.
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Affiliation(s)
- Jinghui Li
- 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.
| | - Wenting Zhang
- College of Chemistry and Chemical Engineering, Yantai University, Yantai, Shandong 264005, P. R. China
| | - Wei Qin
- 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.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, P. R. China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, P. R. China
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3
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Anand G, Safaripour S, Snoeyink C. Dielectric polarization-based separations in an ionic solution. RSC Adv 2023; 13:22185-22192. [PMID: 37492504 PMCID: PMC10363714 DOI: 10.1039/d3ra03169a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/23/2023] [Indexed: 07/27/2023] Open
Abstract
A novel non-electrophoretic, electric field-based separation mechanism capable of transporting ions based on their dielectric properties is presented here for the first time. Though this polarization-based mechanism behaves similarly to dielectrophoresis, the separation mechanism is remarkably very efficient at small length scales compared to any dielectrophoretic separation mechanism for particles. For an applied electric field of strength as low as ∼0.75 MV m-1 across a 100 μm channel, the working solute - sodium fluorescein - is shown to decrease in its concentration by ≈20% in electric field region relative to the non electric field region. The existing macroscopic theoretical models like electrohydrodynamics and equilibrium thermodynamics are shown to underestimate the concentration change by two orders of magnitude for the same electric field strength. This surprisingly large difference between theory and experimental results suggests that the electric field-based equilibrium thermodynamic model lacks a key physics.
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Affiliation(s)
- Gaurav Anand
- Department of Mechanical and Aerospace Engineering, University at Buffalo Buffalo USA
| | - Samira Safaripour
- Department of Mechanical and Aerospace Engineering, University at Buffalo Buffalo USA
| | - Craig Snoeyink
- Department of Mechanical and Aerospace Engineering, University at Buffalo Buffalo USA
- University at Buffalo 211 Bell Hall Buffalo 14260 NY USA
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4
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Bahro C, Goswami S, Gernhart S, Koley D. Calibration-free Solid-State Ion-Selective Electrode Based on a Polarized PEDOT/PEDOT-S-Doped Copolymer as Back Contact. Anal Chem 2022; 94:8302-8308. [DOI: 10.1021/acs.analchem.2c00748] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher Bahro
- Department of Chemistry, Oregon State University, Corvallis 97330, Oregon, United States
| | - Subir Goswami
- Department of Chemistry, Oregon State University, Corvallis 97330, Oregon, United States
| | - Sarah Gernhart
- Department of Chemistry, Oregon State University, Corvallis 97330, Oregon, United States
| | - Dipankar Koley
- Department of Chemistry, Oregon State University, Corvallis 97330, Oregon, United States
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5
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Kisiel A, Michalska A, Maksymiuk K. Bypassed ion-selective electrodes – self-powered polarization for tailoring of sensor performance. Analyst 2022; 147:2764-2772. [DOI: 10.1039/d2an00458e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bypass circuit with zinc wire induces spontaneous charge flow: oxidation of zinc and reduction of the solid contact of K-ISE. This effect is helpful in the improvement of analytical parameters of K-ISE.
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Affiliation(s)
- Anna Kisiel
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Agata Michalska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Krzysztof Maksymiuk
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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6
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Rho J, Yeon SY, Chung TD. Sensitivity-Tunable and Disposable Ion-Sensing Platform Based on Reverse Electrodialysis. Anal Chem 2020; 92:8776-8783. [DOI: 10.1021/acs.analchem.0c00142] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Jihun Rho
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Song Yi Yeon
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Taek Dong Chung
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
- Advanced Institutes of Convergence Technology, Suwon-Si, Gyeonggi-do 16229, Republic of Korea
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7
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Jia F, Hupatz H, Yang LP, Schröder HV, Li DH, Xin S, Lentz D, Witte F, Xie X, Paulus B, Schalley CA, Jiang W. Naphthocage: A Flexible yet Extremely Strong Binder for Singly Charged Organic Cations. J Am Chem Soc 2019; 141:4468-4473. [PMID: 30785740 DOI: 10.1021/jacs.9b00445] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a quite flexible naphthol-based cage (so-called "naphthocage") which adopts a self-inclusion conformation in its free state and is able to bind singly charged organic cations extremely strongly ( Ka > 107 M-1). Ion-selective electrodes prepared with this naphthocage show a super-Nernstian response to acetylcholine. In addition, the highly stable complex (1010 M-1) between ferrocenium and the naphthocage can be switched electrochemically, which lays a basis for its application in stimuli-responsive materials.
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Affiliation(s)
- Fei Jia
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany.,Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology , Xueyuan Boulevard 1088 , Shenzhen 518055 , China
| | - Henrik Hupatz
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Liu-Pan Yang
- Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology , Xueyuan Boulevard 1088 , Shenzhen 518055 , China
| | - Hendrik V Schröder
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Dong-Hao Li
- Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology , Xueyuan Boulevard 1088 , Shenzhen 518055 , China
| | - Shan Xin
- Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology , Xueyuan Boulevard 1088 , Shenzhen 518055 , China
| | - Dieter Lentz
- Institut für Chemie und Biochemie , Freie Universtät Berlin , Fabeckstrasse 34-36 , 14195 Berlin , Germany
| | - Felix Witte
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Xiaojiang Xie
- Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology , Xueyuan Boulevard 1088 , Shenzhen 518055 , China
| | - Beate Paulus
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Christoph A Schalley
- Institut für Chemie und Biochemie , Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Wei Jiang
- Department of Chemistry and Shenzhen Grubbs Institute , Southern University of Science and Technology , Xueyuan Boulevard 1088 , Shenzhen 518055 , China
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8
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Liu S, Ding J, Qin W. Current pulse based ion-selective electrodes for chronopotentiometric determination of calcium in seawater. Anal Chim Acta 2018; 1031:67-74. [DOI: 10.1016/j.aca.2018.06.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 06/04/2018] [Accepted: 06/07/2018] [Indexed: 10/14/2022]
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9
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Ding J, Yu N, Wang X, Qin W. Sequential and Selective Detection of Two Molecules with a Single Solid-Contact Chronopotentiometric Ion-Selective Electrode. Anal Chem 2018; 90:1734-1739. [DOI: 10.1021/acs.analchem.7b03522] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Jiawang Ding
- 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, People’s Republic of China
| | - Nana Yu
- Department
of Environmental Sciences, Key Laboratory of Watershed Science and
Health of Zhejiang Province, Wenzhou Medical University, Wenzhou 325035, People’s Republic of China
| | - Xuedong Wang
- Department
of Environmental Sciences, Key Laboratory of Watershed Science and
Health of Zhejiang Province, Wenzhou Medical University, Wenzhou 325035, People’s Republic of China
| | - Wei Qin
- 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, People’s Republic of China
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10
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Integrated multi-ISE arrays with improved sensitivity, accuracy and precision. Sci Rep 2017; 7:44771. [PMID: 28303939 PMCID: PMC5356001 DOI: 10.1038/srep44771] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/13/2017] [Indexed: 01/22/2023] Open
Abstract
Increasing use of ion-selective electrodes (ISEs) in the biological and environmental fields has generated demand for high-sensitivity ISEs. However, improving the sensitivities of ISEs remains a challenge because of the limit of the Nernstian slope (59.2/n mV). Here, we present a universal ion detection method using an electronic integrated multi-electrode system (EIMES) that bypasses the Nernstian slope limit of 59.2/n mV, thereby enabling substantial enhancement of the sensitivity of ISEs. The results reveal that the response slope is greatly increased from 57.2 to 1711.3 mV, 57.3 to 564.7 mV and 57.7 to 576.2 mV by electronic integrated 30 Cl− electrodes, 10 F− electrodes and 10 glass pH electrodes, respectively. Thus, a tiny change in the ion concentration can be monitored, and correspondingly, the accuracy and precision are substantially improved. The EIMES is suited for all types of potentiometric sensors and may pave the way for monitoring of various ions with high accuracy and precision because of its high sensitivity.
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11
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Kofler J, Nau S, List-Kratochvil EJW. A paper based, all organic, reference-electrode-free ion sensing platform. J Mater Chem B 2015; 3:5095-5102. [DOI: 10.1039/c5tb00387c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a reference-electrode free, all organic K+ sensitive ion sensing platform fabricated by simplest means on a plain sheet of paper.
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Affiliation(s)
- Johannes Kofler
- NanoTecCenter Weiz Forschungsgesellschaft m.b.H
- A-8160 Weiz
- Austria
| | - Sebastian Nau
- NanoTecCenter Weiz Forschungsgesellschaft m.b.H
- A-8160 Weiz
- Austria
| | - Emil J. W. List-Kratochvil
- NanoTecCenter Weiz Forschungsgesellschaft m.b.H
- A-8160 Weiz
- Austria
- Institute of Solid State Physics
- Graz University of Technology
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12
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Sairi M, Arrigan DW. Electrochemical detection of ractopamine at arrays of micro-liquid | liquid interfaces. Talanta 2015; 132:205-14. [DOI: 10.1016/j.talanta.2014.08.060] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/22/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
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13
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14
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Ding J, Wang X, Qin W. Pulsed galvanostatic control of a polymeric membrane ion-selective electrode for potentiometric immunoassays. ACS APPLIED MATERIALS & INTERFACES 2013; 5:9488-9493. [PMID: 24015672 DOI: 10.1021/am402245f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Pulsed galvanostatic control of ion fluxes across polymeric membrane ion-selective electrodes (ISEs) is an emerging field for potentiometric sensing. Herein we report a novel potentiometric enzyme immunoassay based on current-controlled release of an enzyme substrate, which eliminates the addition of marker ions in the sample solution. In this method, the carboxylated poly(vinyl chloride) matrix at the outer layer of the ISE membrane is employed to attach a primary antibody. A sandwich immunoassay with an alkaline phosphatase labeled antibody (ALP-Ab) as the reporter is used for the determination of human IgG (as a model protein). The large difference between the lipophilicity of the substrate ion and that of the product ion allows p-nitrophenyl phosphate to be used as the enzyme substrate for potentiometric immunosensors. After the immunoreactions, the captured ALP-Ab catalyzes the hydrolysis of the substrate ions released at the sample-membrane interface by using the pulsed galvanostatic technique. This process can be potentiometrically determined by measuring the open circuit potential of the ISE. Under optimal conditions, the potential response of the proposed immunosensor is proportional to the concentration of human IgG in the range of 50-1000 ng/mL with a detection limit of 30 ng/mL (3σ). Owing to simplicity and independence of sample volume and sample turbidity, the proposed potentiometric immunoassay offers a viable alternative to those based on optical absorbance.
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Affiliation(s)
- Jiawang Ding
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS) , Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China
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15
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Skórska L, Michalska A, Wojciechowski M, Bulska E, Maksymiuk K. Estimation of primary silver ions contents in poly(vinyl chloride) ion-selective membranes using chronopotentiometry and mass spectrometry. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2011.12.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Cheng C, Tian X, Guo Y, Li Y, Yuan H, Xiao D. Large enhancement of sensitivity and a wider working range of glass pH electrode with amperometric and potentiometric responses. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.08.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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17
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Pawłowski P, Kisiel A, Michalska A, Maksymiuk K. Potentiometric responses of ion-selective electrodes after galvanostatically controlled incorporation of primary ions. Talanta 2011; 84:814-9. [DOI: 10.1016/j.talanta.2011.02.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 02/02/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
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18
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Gemene KL, Meyerhoff ME. Reversible detection of heparin and other polyanions by pulsed chronopotentiometric polymer membrane electrode. Anal Chem 2010; 82:1612-5. [PMID: 20121058 DOI: 10.1021/ac902836e] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first fully reversible polymeric membrane-based sensor for the anticoagulant heparin and other polyanions using a pulsed chronopotentiometry (pulstrode) measurement mode is reported. Polymeric membranes containing a lipophilic inert salt of the form R(+)R(-) (where R(+) and R(-) are tridodecylmethylammonium (TDMA(+)) and dinonylnaphthalene sulfonate (DNNS(-)), respectively) are used to suppress unwanted spontaneous ion extractions under zero-current equilibrium conditions. An anodic galvanostatic current pulse applied across the membrane perturbs the equilibrium lipophilic ion distribution within the membrane phase in such a way that anions/polyanions are extracted into the membrane from the sample. The membrane is then subjected to an open-circuit zero current state for a short period, and finally a 0 V vs reference electrode potentiostatic pulse is applied to restore the membrane to its initial full equilibrium condition. Potentials are sampled as average values during the last 10% of the 0.5 s open circuit phase of the measurement cycle. Fully reversible and reproducible electromotive force (emf) responses are observed for heparin, pentosan polysulfate (PPS), chondroitin sulfate (CS), and oversulfated chondroitin sulfate (OSCS), with the magnitude of the potentiometric response proportional to charge density of the polyanions. The sensor provides an emf response related to heparin concentrations in the range of 1-20 U/mL. The responses to variations in heparin levels and toward other polyanions of the pulstrode configuration are analogous to the already established single-use, nonreversible potentiometric polyion sensors based on membranes doped only with the lipophilic anion exchanger TDMA(+).
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19
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Zook JM, Bodor S, Gyurcsányi RE, Lindner E. Interpretation of chronopotentiometric transients of ion-selective membranes with two transition times. J Electroanal Chem (Lausanne) 2010; 638:254-261. [PMID: 20161602 DOI: 10.1016/j.jelechem.2009.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Passing currents through ion-selective membranes has contributed to the development of a variety of novel methods. In this work, chronopotentiometric (CP) transients with two transition times (breakpoints) are presented for the first time, with the theoretical interpretation of such voltage transients. The validity of our theory has been confirmed in experiments utilizing ETH 5294 chromoionophore-based pH sensitive membranes with and without lipophilic background electrolyte and ETH 5234 ionophore-based calcium selective membranes in which the ionophore forms 3:1 complexes with Ca(2+) ions. The conditions under which two breakpoints can be identified in the chronopotentiometric voltage transients are discussed.Spectroelectrochemical microscopy (SpECM) is used to show that the two breakpoints in the CP curves emerge approximately when the free ionophore and ion-ionophore complex concentrations approach zero at the opposite membrane-solution interfaces. The two breakpoint times can be utilized to follow simultaneously the concentration changes of the free ionophore, the ion-ionophore complex, and the mobile anionic sites in cation-selective membranes. In membranes with known composition, the time instances where breakpoints occur can be used to estimate the free ionophore and the ion-ionophore complex diffusion coefficients.
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Affiliation(s)
- Justin M Zook
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN 38152, USA
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20
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Zook JM, Lindner E. Reverse current pulse method to restore uniform concentration profiles in ion-selective membranes. 1. Galvanostatic pulse methods with decreased cycle time. Anal Chem 2009; 81:5146-54. [PMID: 19459603 DOI: 10.1021/ac801984d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The applications of ion-selective electrodes (ISEs) have been broadened through the introduction of galvanostatic current pulse methods in potentiometric analysis. An important requirement in these applications is the restoration of the uniform equilibrium concentration profiles in the ISE membrane between each measurement. The simplest restoration method is zero-current relaxation, in which the membrane relaxes under open-circuit conditions in a diffusion-controlled process. This paper presents a novel restoration method using a reverse current pulse. An analytic model for this restoration method is derived to predict the concentration profiles inside ISE membranes following galvanostatic current pulses. This model allows the calculation of the voltage transients as the membrane voltage relaxes back toward its zero-current equilibrium value. The predicted concentration profiles and voltage transients are confirmed using spectroelectrochemical microscopy (SpECM). The reverse current restoration method described in this paper reduces the voltage drift and voltage error by 10-100 times compared to the zero-current restoration method. Therefore, this new method provides faster and more reproducible voltage measurements in most chronopotentiometric ISE applications, such as improving the detection limit and determining concentrations and diffusion coefficients of membrane species. One limitation of the reverse current restoration method is that it cannot be used in a few applications that require background electrolyte loaded membranes without excess of lipophilic cation exchanger.
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Affiliation(s)
- Justin M Zook
- Department of Biomedical Engineering, The University of Memphis, 330 Engineering Technology Building, Memphis, Tennessee 38152, USA
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21
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Gemene KL, Bakker E. Measurement of total calcium by flash chronopotentiometry at polymer membrane ion-selective electrodes. Anal Chim Acta 2009; 648:240-5. [DOI: 10.1016/j.aca.2009.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 04/29/2009] [Accepted: 07/02/2009] [Indexed: 11/29/2022]
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22
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Zook JM, Lindner E. Reverse Current Pulse Method To Restore Uniform Concentration Profiles in Ion-Selective Membranes. 2. Comparison of the Efficiency of the Different Protocols. Anal Chem 2009; 81:5155-64. [DOI: 10.1021/ac802065h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Justin M. Zook
- Department of Biomedical Engineering, The University of Memphis, 330 Engineering Technology Building, Memphis, Tennessee 38152
| | - Ernő Lindner
- Department of Biomedical Engineering, The University of Memphis, 330 Engineering Technology Building, Memphis, Tennessee 38152
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23
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Zook JM, Langmaier J, Lindner E. Current-polarized ion-selective membranes: The influence of plasticizer and lipophilic background electrolyte on concentration profiles, resistance, and voltage transients. SENSORS AND ACTUATORS. B, CHEMICAL 2009; 136:410-418. [PMID: 20161192 PMCID: PMC2728498 DOI: 10.1016/j.snb.2008.12.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Lipophilic background electrolytes consisting of a lipophilic cation and a lipophilic anion, such as tetradodecylammonium tetrakis(4-chlorophenyl) borate (ETH 500), or bis(triphenylphosphoranylidene) ammonium tetrakis[3,5bis(trifluoromethyl) phenyl] borate (BTPPATFPB) are incorporated into the membranes of ion-selective electrodes (ISEs) to improve the detection limit and selectivity of the electrodes and decrease the resistance of the sensing membrane. In this work, spectroelectrochemical microscopy (SpECM) is used in conjunction with chronopotentiometry to quantify the effects of a lipophilic background electrolyte on the concentration profiles induced inside current-polarized membranes and on the measured voltage transients in chronopotentiometric experiments. In agreement with the theoretical model, the lipophilic background electrolyte incorporated into o-NPOE or DOS plasticized membranes decreases the membrane resistance and thus the contribution of migration in the overall transport across ion-selective membranes. Consequently, it has a significant influence on the changing concentration profiles of the ion-ionophore complex during chronopotentiometric experiments.
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Affiliation(s)
- Justin M. Zook
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN 38152, USA
| | - Jan Langmaier
- J. Heyrovsky Institute of Physical Chemistry and Electrochemistry, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Ernő Lindner
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN 38152, USA
- 330 Engineering Technology, The University of Memphis, Memphis, TN 38152, , ,
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Mikhel’son KN. Electrochemical sensors based on ionophores: Current state, trends, and prospects. RUSS J GEN CHEM+ 2009. [DOI: 10.1134/s1070363208120268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Xu Y, Bakker E. Ion channel mimetic chronopotentiometric polymeric membrane ion sensor for surface-confined protein detection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:568-573. [PMID: 19067579 PMCID: PMC2664528 DOI: 10.1021/la802728p] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The operation of ion channel sensors is mimicked with functionalized polymeric membrane electrodes, using a surface confined affinity reaction to impede the electrochemically imposed ion transfer kinetics of a marker ion. A membrane surface biotinylated by covalent attachment to the polymeric backbone is used here to bind to the protein avidin as a model system. The results indicate that the protein accumulates on the ion-selective membrane surface, partially blocking the current-induced ion transfer across the membrane/aqueous sample interface, and subsequently decreases the potential jump in the so-called super-Nernstian step that is characteristic of a surface depletion of the marker ion. The findings suggest that such a potential drop could be utilized to measure the concentration of protein in the sample. Because the sensitivity of protein sensing is dependent on the effective blocking of the active surface area, it can be improved with a hydrophilic nanopore membrane applied on top of the biotinylated ion-selective membrane surface. On the basis of cyclic voltammetry characterization, the nanoporous membrane electrodes can indeed be understood as a recessed nanoelectrode array. The results show that the measuring range for protein sensing on nanopore electrodes is shifted to lower concentrations by more than 1 order of magnitude, which is explained with the reduction of surface area by the nanopore membrane and the related more effective hemispherical diffusion pattern.
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Affiliation(s)
- Yida Xu
- Department of Chemistry, Purdue University, Indiana 47907, USA
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Lindner E, Gyurcsányi RE. Quality control criteria for solid-contact, solvent polymeric membrane ion-selective electrodes. J Solid State Electrochem 2008. [DOI: 10.1007/s10008-008-0608-1] [Citation(s) in RCA: 243] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Bodor S, Zook JM, Lindner E, Tóth K, Gyurcsányi RE. Chronopotentiometric method for the assessment of ionophore diffusion coefficients in solvent polymeric membranes. J Solid State Electrochem 2008. [DOI: 10.1007/s10008-008-0614-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Affiliation(s)
- Benjamin J Privett
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Element profiles in galvanostatically polarized K+-selective all-solid-state sensors with poly(vinyl chloride)-based membranes. J Solid State Electrochem 2008. [DOI: 10.1007/s10008-008-0578-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Gemene KL, Bakker E. Direct sensing of total acidity by chronopotentiometric flash titrations at polymer membrane ion-selective electrodes. Anal Chem 2008; 80:3743-50. [PMID: 18370399 PMCID: PMC2574779 DOI: 10.1021/ac701983x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polymer membrane ion-selective electrodes containing lipophilic ionophores are traditionally interrogated by zero current potentiometry, which, ideally, gives information on the sample activity of ionic species. It is shown here that a discrete cathodic current pulse across an H (+)-selective polymeric membrane doped with the ionophore ETH 5294 may be used for the chronopotentiometric detection of pH in well-buffered samples. However, a reduction in the buffer capacity leads to large deviations from the expected Nernstian response slope. This is explained by the local depletion of hydrogen ions at the sample-membrane interface as a result of the galvanostatically imposed ion flux in direction of the membrane. This depletion is found to be a function of the total acidity of the sample and can be directly monitored chronopotentiometrically in a flash titration experiment. The subsequent application of a baseline potential pulse reverses the extraction process of the current pulse, allowing one to interrogate the sample with minimal perturbation. In one protocol, total acidity is found to be proportional to the magnitude of applied current at the flash titration end point. More conveniently, the square root of the flash titration end point time observed at a fixed applied current is a linear function of the total acid concentration. This suggests that it is possible to perform rapid localized pH titrations at ion-selective electrodes without the need for volumetric titrimetry. The technique is explored here for acetic acid, MES and citric acid with promising results. Polymeric membrane electrodes based on poly(vinyl chloride) plasticized with o-nitrophenyl octyl ether in a 1:2 mass ratio may be used for the detection of acids of up to ca. 1 mM concentration, with flash titration times on the order of a few seconds. Possible limitations of the technique are discussed, including variations of the acid diffusion coefficients and influence of electrical migration.
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Affiliation(s)
| | - Eric Bakker
- * To whom correspondence should be addressed.
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Zook JM, Buck RP, Langmaier J, Lindner E. Mathematical model of current-polarized ionophore-based ion-selective membranes. J Phys Chem B 2008; 112:2008-15. [PMID: 18217742 DOI: 10.1021/jp074612i] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A mathematical model is presented to describe the effects of constant current on ion-selective membranes using theta functions. The model provides exact analytic solutions for calculating the concentration polarization of the ionophore, the ion-ionophore complex, and the charged mobile sites in space and time within the membrane. It also predicts the time course of the membrane potential and the electric field inside the membrane following the application of constant current. This analytic solution is faster to compute than numerical simulations and provides the solution for any given time or position directly. The simulated concentration profiles compare favorably with concentration profiles recorded experimentally using spectro-electrochemical microscopy.
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Affiliation(s)
- Justin M Zook
- Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee 38152, USA
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Influence of galvanostatic polarisation on evolution of ion concentration profiles in ion-selective membranes, studied by means of laser ablation inductively coupled plasma mass spectrometry. Electrochem commun 2008. [DOI: 10.1016/j.elecom.2007.10.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
This paper gives an overview of the newest developments of polymeric membrane ion-selective electrodes. A short essence of the underlying theory is given, emphasizing how the electromotive force may be used to assess binding constants of the ionophore, and how the selectivity and detection limit are related to the underlying membrane processes. The recent developments in lowering the detection limits of ISEs are described, including recent approaches of developing all solid state ISEs, and breakthroughs in detecting ultra-small quantities of ions at low concentrations. These developments have paved the way to use potentiometric sensors as in ultra-sensitive affinity bioanalysis in conjunction with nanoparticle labels. Recent results establish that potentiometry compares favorably to electrochemical stripping analysis. Other new developments with ion-selective electrodes are also described, including the concept of backside calibration potentiometry, controlled current coulometry, pulsed chronopotentiometry, and localized flash titration with ion-selective membranes to design sensors for the direct detection of total acidity without net sample perturbation. These developments have further opened the field for exciting new possibilities and applications.
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Affiliation(s)
- Eric Bakker
- Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, Perth, WA 6845, Australia
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Perera H, Shvarev A. Unbiased selectivity coefficients obtained for the pulsed chronopotentiometric polymeric membrane ion sensors. J Am Chem Soc 2007; 129:15754-5. [PMID: 18052379 DOI: 10.1021/ja076821m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report here on the successful observation of the unbiased thermodynamic selectivity of ion-selective sensors working in normal pulse chronopotentiometric mode (pulstrodes). In contrast to ion-selective electrodes, the pulstrodes do not require careful counterbalancing of the transmembrane ionic fluxes to achieve unbiased thermodynamic selectivity. The pulstrodes can work under asymmetric conditions, which are often encountered in practice. The composition of the inner filling solution did not affect the sensor response, indicating that the transmembrane flux of primary ions was indeed effectively suppressed in the absence of ion exchanger. For the K-selective sensor considered here, an improvement of Mg discrimination by a factor of 1000 was demonstrated.
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Affiliation(s)
- Hasini Perera
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, USA
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Bakker E, Bhakthavatsalam V, Gemene KL. Beyond potentiometry: robust electrochemical ion sensor concepts in view of remote chemical sensing. Talanta 2007; 75:629-35. [PMID: 18585124 DOI: 10.1016/j.talanta.2007.10.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Accepted: 10/11/2007] [Indexed: 11/25/2022]
Abstract
For about 100 years, potentiometry with ion-selective electrodes has been one of the dominating electroanalytical techniques. While great advances in terms of selective chemistries and materials have been achieved in recent years, the basic manner in which ion-selective membranes are used has not fundamentally changed. The potential readings are directly co-dependent on the potential at the reference electrode, which requires maintenance and for which very few accepted alternatives have been proposed. Fouling or clogging of the exposed electrode surfaces will lead to changes in the observed potential. At the same time, the Nernst equation predicts quite small potential changes, on the order of millivolts for concentration changes on the order of a factor two, making frequent recalibration, accurate temperature control and electrode maintenance key requirements of routine analytical measurements. While the relatively advanced selective materials developed for ion-selective sensors would be highly attractive for low power remote sensing application, one should consider solutions beyond classical potentiometry to make this technology practically feasible. This paper evaluates some recent examples that may be attractive solutions to the stated problems that face potentiometric measurements. These include high-amplitude sensing approaches, with sensitivities that are an order of magnitude larger than predicted by the Nernst equation; backside calibration potentiometry, where knowledge of the magnitude of the potential is irrelevant and the system is evaluated from the backside of the membrane; controlled current coulometry with ion-selective membranes, an attractive technique for calibration-free reagent delivery without the need for standards or volumetry; localized electrochemical titrations at ion-selective membranes, making it possible to design sensors that directly monitor parameters such as total acidity for which volumetric techniques were traditionally used; and controlled potential coulometry, where all ions of interest are selectively transferred into the ion-selective organic phase, forming a calibration-free technique that would be exquisitely suitable for remote sensing applications.
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Affiliation(s)
- Eric Bakker
- Department of Chemistry, 560 Oval Drive, Purdue University, West Lafayette, IN 47907, USA
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Xu Y, Xu C, Shvarev A, Becker T, De Marco R, Bakker E. Kinetic modulation of pulsed chronopotentiometric polymeric membrane ion sensors by polyelectrolyte multilayers. Anal Chem 2007; 79:7154-60. [PMID: 17711298 PMCID: PMC2883718 DOI: 10.1021/ac071201p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polymeric membrane ion-selective electrodes are normally interrogated by zero current potentiometry, and their selectivity is understood to be primarily dependent on an extraction/ion-exchange equilibrium between the aqueous sample and polymeric membrane. If concentration gradients in the contacting diffusion layers are insubstantial, the membrane response is thought to be rather independent of kinetic processes such as surface blocking effects. In this work, the surface of calcium-selective polymeric ion-selective electrodes is coated with polyelectrolyte multilayers as evidenced by zeta potential measurements, atomic force microscopy, and electrochemical impedance spectroscopy. Indeed, such multilayers have no effect on their potentiometric response if the membranes are formulated in a traditional manner, containing a lipophilic ion exchanger and a calcium-selective ionophore. However, drastic changes in the potential response are observed if the membranes are operated in a recently introduced kinetic mode using pulsed chronopotentiometry. The results suggest that the assembled nanostructured multilayers drastically alter the kinetics of ion transport to the sensing membrane, making use of the effect that polyelectrolyte multilayers have different permeabilities toward ions with different valences. The results have implications to the design of chemically selective ion sensors since surface-localized kinetic limitations can now be used as an additional dimension to tune the operational ion selectivity.
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Affiliation(s)
- Yida Xu
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA
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37
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Perera H, Fordyce K, Shvarev A. Pulsed galvanostatic control of solid-state polymeric ion-selective electrodes. Anal Chem 2007; 79:4564-73. [PMID: 17488093 DOI: 10.1021/ac062123t] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report on galvanostatically controlled solid-state reversible ion-selective sensors for cationic analytes utilizing a conducting polymer as a transduction layer between the polymeric membrane and electron-conductive substrate. The instrumental control of polymeric membrane ion-selective electrodes based on electrochemically induced periodic ion extraction in alternating galvanostatic/potentiostatic mode was introduced recently creating exciting possibilities to detect clinically relevant polyions such as heparin and protamine and drastically improve the sensitivity of ion-selective sensors limited by the Nernst equation. The present study forms the basis for development of reliable, robust, and possibly maintenance-free sensors that can be fabricated using screen-printing technology. Various aspects of the development of solid-contact galvanostatically controlled ion-selective electrodes with a conducting polymer as a transduction layer are considered in the present work on the example of a model system based on a sodium-selective membrane. The protamine-selective solid-contact sensor was fabricated and characterized, which represents the next step toward commercially viable polyion sensing technology. A substantial improvement of a low detection limit (0.03 mg L-1) was achieved. A simplified diffusion-based theoretical model is discussed predicting the polarization at the interface of the conducting polymer and the membrane, which can cause the disruption of the sensor response function at relatively small current densities.
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Affiliation(s)
- Hasini Perera
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, USA
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Gemene KL, Shvarev A, Bakker E. Selectivity enhancement of anion-responsive electrodes by pulsed chronopotentiometry. Anal Chim Acta 2006; 583:190-6. [PMID: 17386545 PMCID: PMC1826444 DOI: 10.1016/j.aca.2006.09.042] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 09/20/2006] [Accepted: 09/22/2006] [Indexed: 11/20/2022]
Abstract
A large and robust selectivity improvement of ion-selective electrodes is presented for the measurement of abundant ions. An improvement in selectivity by more than two orders of magnitude has been attained for the hydrophilic chloride ions measured in a dilute background of the lipophilic ions perchlorate and salicylate in a pulsed chronopotentiometric measurement mode. This is attributed to a robust kinetic discrimination of the dilute lipophilic ions in this measuring mode, which is not possible to achieve in classical potentiometry. Maximum tolerable concentrations of the interfering ions are found to be on the order of 30 microM before causing substantial changes in potential. As an example of practical relevance, the robust detection of chloride in 72 microM salicylate (reflecting 1:10 diluted blood) with a detection limit of 0.5 mM chloride is demonstrated. Corresponding potentiometric sensors did not give a useful chloride response under these conditions.
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Abstract
A novel concept of photoresponsive ion-selective optical sensor is described. Photochemical reactions can be utilized to generate and control ion fluxes in an ion-selective optode in the same manner as nonequilibrium electrochemical methods have been used in ion-selective electrodes. In contrast to their equilibrium counterparts, the photoresponsive pH-selective ion optodes are sensitive to both the buffer capacity of the sample and activity of hydrogen ions. Active optical probes are especially attractive for intracellular applications because they can be fabricated as submicron-sized beads. Common optical techniques, such as fluorescence microscopy and flow cytometry, can be combined with active ion probes with only minor modification of the existing experimental setup.
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Affiliation(s)
- Alexey Shvarev
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA.
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