1
|
Baek SH, Yun J, Lee SH, Lee HW, Kwon Y, Park KR, Song Y, Kim BS, Kwak R, Hwang H, Jeong DW. Real-time analysis and prediction method of ion concentration using the effect of O-H stretching bands in aqueous solutions based on ATR-FTIR spectroscopy. RSC Adv 2024; 14:20073-20080. [PMID: 38915330 PMCID: PMC11194664 DOI: 10.1039/d4ra01473a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 06/14/2024] [Indexed: 06/26/2024] Open
Abstract
Analyzing the concentration of ions in aqueous solutions in real-time plays an important role in the fields of chemistry and biology. Traditional methods for measuring ion concentrations, such as concentration analysis by measuring electrical conductivity, inductively coupled plasma mass spectrometry, and ion chromatography, have been used in many research fields. However, these methods are limited in determining ion concentrations instantaneously. Fourier-transform infrared-attenuated total reflectance (ATR-FTIR) spectroscopy provides a new approach for determining ion concentrations in aqueous solutions. This allows for fast analysis without pretreatment and is scalable for real-time measurements. In this study, we present a method for measuring ion concentrations by examining ion-water interactions in the O-H stretching band of aqueous solutions using ATR-FTIR spectroscopy. Five aqueous solutions, namely LiCl + HCl, LiOH + HCl, LiOH, Li3PO4, and NaCl were used in the experiments and prepared at concentrations between 0.5-2 M. The ion concentrations in the prepared aqueous solutions were measured using ATR-FTIR spectroscopy. We observed that the difference in absorbance increased and decreased linearly with changes in concentration. The concentration of ions in the aqueous solution could be measured by validating the designed linear regression analysis function model. In this study, we proposed five linear regression analysis function models, all of which showed high coefficients of determination above 0.9, with the highest coefficient of determination reaching 0.9969. These results show that ATR-FTIR spectroscopy has the potential to be applied as a rapid and simple concentration analysis system.
Collapse
Affiliation(s)
- So Hyun Baek
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
- Department of Material Science Engineering, Inha University Incheon 22212 Republic of Korea
| | - Jeungjai Yun
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
- Department of Mechanical Convergence Engineering, Hanyang University Seoul 04763 Republic of Korea
| | - Seung-Hwan Lee
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| | - Hyun-Woo Lee
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| | - Yongbum Kwon
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| | - Kee-Ryung Park
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| | - Yoseb Song
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| | - Bum Sung Kim
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| | - Rhokyun Kwak
- Department of Mechanical Convergence Engineering, Hanyang University Seoul 04763 Republic of Korea
| | - Haejin Hwang
- Department of Material Science Engineering, Inha University Incheon 22212 Republic of Korea
| | - Da-Woon Jeong
- Department of Korea National Institute of Rare Metals, Korea Institute of Industrial Technology Incheon 21655 Republic of Korea +82-32-226-1374 +82-32-226-1362
| |
Collapse
|
2
|
Rousseau CR, Chipangura YE, Stein A, Bühlmann P. Effect of Ion Identity on Capacitance and Ion-to-Electron Transduction in Ion-Selective Electrodes with Nanographite and Carbon Nanotube Solid Contacts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1785-1792. [PMID: 38198594 DOI: 10.1021/acs.langmuir.3c03027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
The use of large surface area carbon materials as transducers in solid-contact ion-selective electrodes (ISEs) has become widespread. Desirable qualities of ISEs, such as a small long-term drift, have been associated with a high capacitance that arises from the formation of an electrical double layer at the interface of the large surface area carbon material and the ion-selective membrane. The capacitive properties of these ISEs have been observed using a variety of techniques, but the effects of the ions present in the ion-selective membrane on the measured value of the capacitance have not been studied in detail. Here, it is shown that changes in the size and concentration of the ions in the ion-selective membrane as well as the polarity of the polymeric matrix result in capacitances that can vary by up to several hundred percent. These data illustrate that the interpretation of comparatively small differences in capacitance for different types of solid contacts is not meaningful unless the composition of the ion-selective membrane is taken into account.
Collapse
Affiliation(s)
- Celeste R Rousseau
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Yevedzo E Chipangura
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Andreas Stein
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
3
|
Konefał A, Piątek P, Paterczyk B, Maksymiuk K, Michalska A. Ionophore based optical sensors using hydrophilic polymer matrix – Ratiometric, pH independent ion-selective optodes. Talanta 2022. [DOI: 10.1016/j.talanta.2022.124038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
4
|
Damala P, Zdrachek E, Forrest T, Bakker E. Unconditioned Symmetric Solid-Contact Electrodes for Potentiometric Sensing. Anal Chem 2022; 94:11549-11556. [DOI: 10.1021/acs.analchem.2c01728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Polyxeni Damala
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Elena Zdrachek
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Tara Forrest
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Eric Bakker
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| |
Collapse
|
5
|
Pietrzak K, Krstulović N, Blažeka D, Car J, Malinowski S, Wardak C. Metal oxide nanoparticles as solid contact in ion-selective electrodes sensitive to potassium ions. Talanta 2022; 243:123335. [DOI: 10.1016/j.talanta.2022.123335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/08/2022] [Accepted: 02/23/2022] [Indexed: 12/30/2022]
|
6
|
Hydrophobic laser-induced graphene potentiometric ion-selective electrodes for nitrate sensing. Mikrochim Acta 2022; 189:122. [PMID: 35218439 DOI: 10.1007/s00604-022-05233-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 02/15/2022] [Indexed: 10/19/2022]
Abstract
Current solid-contact ion-selective electrodes (ISEs) suffer from signal-to-noise drift and short lifespans partly due to water uptake and the development of an aqueous layer between the transducer and ion-selective membrane. To address these challenges, we report on a nitrate ISE based on hydrophobic laser-induced graphene (LIG) coated with a poly(vinyl) chloride-based nitrate selective membrane. The hydrophobic LIG was created using a polyimide substrate and a double lasing process under ambient conditions (air at 23.0 ± 1.0 °C) that resulted in a static water contact angle of 135.5 ± 0.7° (mean ± standard deviation) in wettability testing. The LIG-ISE displayed a Nernstian response of - 58.17 ± 4.21 mV dec-1 and a limit-of-detection (LOD) of 6.01 ± 1.44 µM. Constant current chronopotentiometry and a water layer test were used to evaluate the potential (emf) signal stability with similar performance to previously published work with graphene-based ISEs. Using a portable potentiostat, the sensor displayed comparable (p > 0.05) results to a US Environmental Protection Agency (EPA)-accepted analytical method when analyzing water samples collected from two lakes in Ames, IA. The sensors were stored in surface water samples for 5 weeks and displayed nonsignificant difference in performance (LOD and sensitivity). These results, combined with a rapid and low-cost fabrication technique, make the development of hydrophobic LIG-ISEs appealing for a wide range of long-term in situ surface water quality applications.
Collapse
|
7
|
Rousseau CR, Honig ML, Bühlmann P. Hydrogels Doped with Redox Buffers as Transducers for Ion-Selective Electrodes. Anal Chem 2021; 94:1143-1150. [PMID: 34932309 DOI: 10.1021/acs.analchem.1c04264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Solid-contact ion-selective electrodes (ISEs) with an unintentional water layer between the sensing membrane and underlying electron conductor are well known to suffer from potential drift caused by the instability of the phase boundary potential between the sensing membrane and the water layer with its uncontrolled ionic composition. The reproducibility and long-term emf stability of ISEs with a miniaturized inner filling solution comprising a hydrogel and a hydrophilic electrolyte have not been studied as thoroughly. Here, such devices are discussed with a view to electrode-to-electrode reproducibility, using both hydrophilic ion-exchange and plasticized PVC membranes, along with a hydrophilic redox buffer composed of ferrocyanide and ferricyanide to control the potential between the hydrogel and the underlying electron conductor. With plasticized PVC sensing membranes, these electrodes showed an E0 reproducibility of ±1.1 mV or better, while with hydrophilic ion-exchange membranes, this variability was slightly larger. Long-term drifts were also assessed with both membranes, and the effect of osmotic pressure on drift was shown to be insignificant for the PVC membranes and very small at most for the hydrophilic membranes.
Collapse
Affiliation(s)
- Celeste R Rousseau
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Madeline L Honig
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
8
|
Lisak G. Reliable environmental trace heavy metal analysis with potentiometric ion sensors - reality or a distant dream. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 289:117882. [PMID: 34364114 DOI: 10.1016/j.envpol.2021.117882] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 07/13/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
Over two decades have passed since polymeric membrane ion-selective electrodes were found to exhibit sufficiently lower detection limits. This in turn brought a great promise to measure trace level concentrations of heavy metals using potentiometric ion sensors at environmental conditions. Despite great efforts, trace analysis of heavy metals using ion-selective electrodes at environmental conditions is still not commercially available. This work will predominantly concentrate on summarizing and evaluating prospects of using potentiometric ion sensors in view of environmental determination of heavy metals in on-site and on-line analysis modes. Challenges associated with development of reliable potentiometric sensors to be operational in environmental conditions will be discussed and reasoning behind unsuccessful efforts to develop potentiometric on-site and on-line environmental ion sensors will be explored. In short, it is now clear that solely lowering the detection limit of the ion-selective electrodes does not guarantee development of successful sensors that would meet the requirement of environmental matrices over long term usage. More pressing challenges of the properties and the performance of the potentiometric sensors must be addressed first before considering extending their sensitivity to low analyte concentrations. These are, in order of importance, selectivity of the ion-selective membrane to main ion followed by the membrane resistance to parallel processes, such as water ingress to the ISM, light sensitivity, change in temperature, presence of gasses in solution and pH and finally resistance of the ion-selective membrane to fouling. In the future, targeted on-site and on-line environmental sensors should be developed, addressing specific environmental conditions. Thus, ion-selective electrodes should be developed with the intention to be suitable to the operational environmental conditions, rather than looking at universal sensor design validated in the idealized and simple sample matrices.
Collapse
Affiliation(s)
- Grzegorz Lisak
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore, 637141, Singapore.
| |
Collapse
|
9
|
Jin X, Saha A, Jiang H, Oduncu MR, Yang Q, Sedaghat S, Maize K, Allebach JP, Shakouri A, Glassmaker N, Wei A, Rahimi R, Alam MA. Steady-State and Transient Performance of Ion-Sensitive Electrodes Suitable for Wearable and Implantable Electro-chemical Sensing. IEEE Trans Biomed Eng 2021; 69:96-107. [PMID: 34101580 DOI: 10.1109/tbme.2021.3087444] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Traditional Potentiometric Ion-selective Electrodes (ISE) are widely used in industrial and clinical settings. The simplicity and small footprint of ISE have encouraged their recent adoption as wearable/implantable sensors for personalized healthcare and precision agriculture, creating a new set of unique challenges absent in traditional ISE. In this paper, we develop a fundamental physics-based model to describe both steady-state and transient responses of ISE relevant for wearable/implantable sensors. The model is encapsulated in a generalized Nernst formula that explicitly accounts for the analyte density, time-dynamics of signal transduction, ion-selective membrane thickness, and other sensor parameters. The formula is validated numerically by self-consistent modeling of multispecies ion-transport and experimentally by interpreting the time dynamics and thickness dependence of thin-film solid-contact and graphene-based ISE sensors for measuring soil nitrate concentration. These fundamental results will support the accelerated development of ISE for wearable/implantable applications.
Collapse
|
10
|
Wang F, Liu Y, Zhang M, Zhang F, He P. Home Detection Technique for Na + and K + in Urine Using a Self-Calibrated all-Solid-State Ion-Selective Electrode Array Based on Polystyrene-Au Ion-Sensing Nanocomposites. Anal Chem 2021; 93:8318-8325. [PMID: 34096282 DOI: 10.1021/acs.analchem.1c01203] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An all-solid-state ion-selective electrode (ASS-ISE) array that is portable and easily miniaturized can meet the needs of home sensing devices for long-term health monitoring. However, their stability and accuracy are affected by the multistep modification required for ASS-ISE manufacturing and the complex background signal of real samples. In this study, a four-channel ISE array with the integration of a calibration channel has been developed based on polystyrene-Au (PS-Au) ion-sensing nanocomposites (PS-Au ISE array) for the home detection of Na+ and K+. The nanocomposites combine target recognition function and ion-electron transduction function and could be modified on the channel surface by direct drop-casting, thus simplifying the preparation process and then improving the stability. Meanwhile, the integrated calibration channel could automatically deduct complex background signals in real sample analysis and thus improve the accuracy. As a result, the proposed self-calibrated PS-Au ISE array showed a near Nernstian behavior for Na+ and K+ in the range of 1 × 10-2 M-1 × 10-4 M, and the detection limits were 6.8 × 10-5 M and 5.5 × 10-5 M in artificial urine. The linear equations can be obtained according to the slopes and intercepts of Na+ and K+, and thus, the concentration of the target ions can be directly read out by combining this PS-Au ISE array with the smart electronic device. Furthermore, the detection results of Na+ and K+ in human urine agreed well with those obtained by ICP-AES, suggesting that this proposed self-calibrated PS-Au ISE array is very suitable for home smart sensing devices, facilitating the health monitoring.
Collapse
Affiliation(s)
- Fan Wang
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, P.R. China
| | - Yujing Liu
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, P.R. China
| | - Mengdi Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, P.R. China
| | - Fan Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, P.R. China
| | - Pingang He
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, P.R. China
| |
Collapse
|
11
|
Keresten V, Solovyeva E, Mikhelson K. The Origin of the Non-Constancy of the Bulk Resistance of Ion-Selective Electrode Membranes within the Nernstian Response Range. MEMBRANES 2021; 11:membranes11050344. [PMID: 34067145 PMCID: PMC8150337 DOI: 10.3390/membranes11050344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022]
Abstract
The dependence of the bulk resistance of membranes of ionophore-based ion-selective electrodes (ISEs) on the composition of mixed electrolyte solutions, within the range of the Nernstian potentiometric response, is studied by chronopotentiometric and impedance measurements. In parallel to the resistance, water uptake by the membranes is also studied gravimetrically. The similarity of the respective curves is registered and explained in terms of heterogeneity of the membranes due to the presence of dispersed aqueous phase (water droplets). It is concluded that the electrochemical equilibrium is established between aqueous solution and the continuous organic phase, while the resistance refers to the membrane as whole, and water droplets hamper the charge transfer across the membranes. In this way, it is explained why the membrane bulk resistance is not constant within the range of the Nernstian potentiometric response of ISEs.
Collapse
|
12
|
Ruiz-Gonzalez A, Choy KL. Integration of an Aerosol-Assisted Deposition Technique for the Deposition of Functional Biomaterials Applied to the Fabrication of Miniaturised Ion Sensors. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:938. [PMID: 33916937 PMCID: PMC8067610 DOI: 10.3390/nano11040938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 12/02/2022]
Abstract
Ion-selective electrodes are at the forefront of research nowadays, with applications in healthcare, agriculture and water quality analysis among others. Despite multiple attempts of miniaturization of these polyvinyl chloride (PVC) gel-based ion sensors, no ion-sensing devices with a thickness below the micrometer range, and operating using open circuit potential, have been developed so far. This work reports the causes of this thickness limitation in potassium-selective sensors. Highly homogeneous ion-sensing films were fabricated by a method based on aerosol assisted chemical vapour deposition, leading to smooth surfaces with 27 ± 11 nm of roughness. Such homogeneity allowed the systematic study of the performance and ionic diffusion properties of the sensing films at sub-micrometer scales. Sensitivities below the Nernst response were found at low thicknesses. The nature of this reduction in sensitivity was studied, and a difference in the superficial and bulk compositions of the films was measured. An optimal configuration was found at 15 µm, with a good selectivity against Na+ (KK+, Na+ = -1.8) a limit of detection in the range of 10-4 M and esponse time below 40 s. The stability of sensors was improved by the deposition of protective layers, which expanded the lifespan of the ion sensors up to 5 weeks while preserving the Nernst sensitivity.
Collapse
Affiliation(s)
| | - Kwang-Leong Choy
- Institute for Materials Discovery, Faculty of Mathematical & Physical Sciences, University College London, 107 Roberts Building, Malet Place, London WC1E 7JE, UK;
| |
Collapse
|
13
|
Cheong YH, Ge L, Lisak G. Highly reproducible solid contact ion selective electrodes: Emerging opportunities for potentiometry - A review. Anal Chim Acta 2021; 1162:338304. [PMID: 33926699 DOI: 10.1016/j.aca.2021.338304] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/20/2021] [Accepted: 02/04/2021] [Indexed: 02/07/2023]
Abstract
The solid contact ion-selective electrodes (SC-ISEs) have been extensively studied in the field of ion sensing as they offer the possibility of miniaturization, are relatively inexpensive in comparison to other analytical techniques and allow straightforward and routine analyses of ions in a number of clinical, environmental and industrial process samples. In recent years, significant interest has grown in the development of SC-ISEs with well-defined interfacialpotentials at the membrane, solid contact, and substrate electrode interfaces. This has resulted in interesting SC-ISEs exhibiting high electrode-to-electrode potential reproducibility, for those made in a single batch of electrodes, some approaching or exceeding those observed in liquid-contact ISEs. The advancement in the potential reproducibility of SC-ISEs has been partially achieved by scrutinizing insufficiently reproducible fabrication methods of SC-ISEs, or by introducing novel control measures or modifiers to components of the ISEs. This paper provides an overview of the methods as well as the challenges in establishing and maintaining reproducible potentials during the fabrication and use of novel SC-ISEs. The rules outlined in the works reviewed may form the basis of further development of cost-effective, user-friendly, limited calibration or calibration-free potentiometric SC-ISEs to achieve reliable ion analyses here and now.
Collapse
Affiliation(s)
- Yi Heng Cheong
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore; Robert Bosch (South East Asia) Pte Ltd, 11 Bishan Street 21, Singapore, 573943, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore, 637141, Singapore
| | - Liya Ge
- Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore, 637141, Singapore
| | - Grzegorz Lisak
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore, 637141, Singapore.
| |
Collapse
|
14
|
Solovyeva EV, Lu H, Khripoun GA, Mikhelson KN, Kazarian SG. In situ ATR-FTIR spectroscopic imaging of PVC, plasticizer and water in solvent-polymeric ion-selective membrane containing Cd2+-selective neutral ionophore. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2020.118798] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
15
|
Kozma J, Papp S, Gyurcsányi RE. Solid-contact ion-selective electrodes based on ferrocene-functionalized multi-walled carbon nanotubes. Electrochem commun 2021. [DOI: 10.1016/j.elecom.2020.106903] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
16
|
Potentiometric Carboxylate Sensors Based on Carbazole-Derived Acyclic and Macrocyclic Ionophores. CHEMOSENSORS 2020. [DOI: 10.3390/chemosensors9010004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Solid-contact ion-selective electrodes with carbazole-derived ionophores were prepared. They were characterized as acetate sensors, but can be used to determine a number of carboxylates. The potentiometric response characteristics (slope, detection limit, selectivity, and pH sensitivity) of sensors prepared with different membrane compositions (ionophore, ionophore concentration, anion exchanger concentration, and plasticizer) were evaluated. The results show that for the macrocyclic ionophores, a larger cavity provided better selectivity. The sensors exhibited modest selectivity for acetate but good selectivity for benzoate. The carbazole-derived ionophores effectively decreased the interference from lipophilic anions, such as bromide, nitrate, iodide, and thiocyanate. The selectivity, detection limit, and linear range were improved by choosing a suitable plasticizer and by reducing the ionophore and anion exchanger concentrations. The influence of the electrode body’s material upon the composition of the plasticized poly(vinyl chloride) membrane, and thus also upon the sensor characteristics, was also studied. The choice of materials for the electrode body significantly affected the characteristics of the sensors.
Collapse
|
17
|
Fan Y, Huang Y, Linthicum W, Liu F, Beringhs AO, Dang Y, Xu Z, Chang SY, Ling J, Huey BD, Suib SL, Ma AWK, Gao PX, Lu X, Lei Y, Shaw MT, Li B. Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)-Solid-State Ion-Selective Electrodes (S-ISEs). ACS Sens 2020; 5:3182-3193. [PMID: 32933249 DOI: 10.1021/acssensors.0c01422] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Long-term accurate and continuous monitoring of nitrate (NO3-) concentration in wastewater and groundwater is critical for determining treatment efficiency and tracking contaminant transport. Current nitrate monitoring technologies, including colorimetric, chromatographic, biometric, and electrochemical sensors, are not feasible for continuous monitoring. This study addressed this challenge by modifying NO3- solid-state ion-selective electrodes (S-ISEs) with poly(tetrafluoroethylene) (PTFE, (C2F4)n). The PTFE-loaded S-ISE membrane polymer matrix reduces water layer formation between the membrane and electrode/solid contact, while paradoxically, the even more hydrophobic PTFE-loaded S-ISE membrane prevents bacterial attachment despite the opposite approach of hydrophilic modifications in other antifouling sensor designs. Specifically, an optimal ratio of 5% PTFE in the S-ISE polymer matrix was determined by a series of characterization tests in real wastewater. Five percent of PTFE alleviated biofouling to the sensor surface by enhancing the negative charge (-4.5 to -45.8 mV) and lowering surface roughness (Ra: 0.56 ± 0.02 nm). It simultaneously mitigated water layer formation between the membrane and electrode by increasing hydrophobicity (contact angle: 104°) and membrane adhesion and thus minimized the reading (mV) drift in the baseline sensitivity ("data drifting"). Long-term accuracy and durability of 5% PTFE-loaded NO3- S-ISEs were well demonstrated in real wastewater over 20 days, an improvement over commercial sensor longevity.
Collapse
Affiliation(s)
- Yingzheng Fan
- Department of Civil & Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yuankai Huang
- Department of Civil & Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Will Linthicum
- Department of Materials Science & Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Fangyuan Liu
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | | | - Yanliu Dang
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Zhiheng Xu
- Department of Civil & Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Shing-Yun Chang
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
- Department of Chemical and Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Jing Ling
- Department of Civil & Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Bryan D. Huey
- Department of Materials Science & Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Steven L. Suib
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Anson W. K. Ma
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
- Department of Chemical and Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Pu-Xian Gao
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Xiuling Lu
- School of Pharmacy, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yu Lei
- Department of Chemical and Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Montgomery T. Shaw
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Baikun Li
- Department of Civil & Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| |
Collapse
|
18
|
Unintended Changes of Ion-Selective Membranes Composition-Origin and Effect on Analytical Performance. MEMBRANES 2020; 10:membranes10100266. [PMID: 32998393 PMCID: PMC7601616 DOI: 10.3390/membranes10100266] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 01/28/2023]
Abstract
Ion-selective membranes, as used in potentiometric sensors, are mixtures of a few important constituents in a carefully balanced proportion. The changes of composition of the ion-selective membrane, both qualitative and quantitative, affect the analytical performance of sensors. Different constructions and materials applied to improve sensors result in specific conditions of membrane formation, in consequence, potentially can result in uncontrolled modification of the membrane composition. Clearly, these effects need to be considered, especially if preparation of miniaturized, potentially disposable internal-solution free sensors is considered. Furthermore, membrane composition changes can occur during the normal operation of sensors—accumulation of species as well as release need to be taken into account, regardless of the construction of sensors used. Issues related to spontaneous changes of membrane composition that can occur during sensor construction, pre-treatment and their operation, seem to be underestimated in the subject literature. The aim of this work is to summarize available data related to potentiometric sensors and highlight the effects that can potentially be important also for other sensors using ion-selective membranes, e.g., optodes or voltammetric sensors.
Collapse
|
19
|
Tshepelevitsh S, Kadam SA, Darnell A, Bobacka J, Rüütel A, Haljasorg T, Leito I. LogP determination for highly lipophilic hydrogen-bonding anion receptor molecules. Anal Chim Acta 2020; 1132:123-133. [PMID: 32980103 DOI: 10.1016/j.aca.2020.07.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 01/31/2023]
Abstract
Lipophilicity, usually expressed as octanol-water partition coefficient (logPo/w), is an important property in biomedical research, drug design and technology. However, high logPo/w values of complex hydrogen-bonding molecules are not easy to measure or calculate. Exemplary problematic molecules are prospective active components (ionophores) of polymeric sensor membranes - the working elements of ion-selective electrodes. High lipophilicities of the membrane components are crucial for the sensor lifetime. In this work, lipophilicities of a wide range of urea-, carbazole- and indolocarbazole-based anion receptor molecules (some newly synthesized) and two common plasticizers were determined using a chromatography-based approach and/or the COSMO-RS method. Very high logPo/w values, up to around 20, i.e. far beyond directly experimentally accessible range, were obtained. The agreement between the two approaches ranged from very good to satisfactory. Based on these results, simple fragment-based equations were developed for quick lipophilicity estimation without any specialized software. Membrane-water partition coefficients for the studied compounds were modeled. Limitations and biases of the used methods are discussed.
Collapse
Affiliation(s)
- Sofja Tshepelevitsh
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
| | - Sandip A Kadam
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
| | - Astrid Darnell
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
| | - Johan Bobacka
- Åbo Akademi University, Johan Gadolin Process Chemistry Centre, Laboratory of Molecular Science and Engineering, Biskopsgatan 8, FI-20500, Turku/Åbo, Finland
| | - Alo Rüütel
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
| | - Tõiv Haljasorg
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia.
| |
Collapse
|
20
|
Papp S, Kozma J, Lindfors T, Gyurcsányi RE. Lipophilic Multi‐walled Carbon Nanotube‐based Solid Contact Potassium Ion‐selective Electrodes with Reproducible Standard Potentials. A Comparative Study. ELECTROANAL 2020. [DOI: 10.1002/elan.202000045] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Soma Papp
- Department of Inorganic and Analytical Chemistry, BME Lendület Chemical Nanosensor Research GroupBudapest University of Technology and Economics Szt. Gellert tér 4 H-1111 Budapest Hungary
| | - József Kozma
- Department of Inorganic and Analytical Chemistry, BME Lendület Chemical Nanosensor Research GroupBudapest University of Technology and Economics Szt. Gellert tér 4 H-1111 Budapest Hungary
| | - Tom Lindfors
- Åbo Akademi University, Johan Gadolin Process Chemistry CentreLaboratory of Molecular Science and Engineering Biskopsgatan 8 FIN-20500 Åbo Finland
| | - Róbert E. Gyurcsányi
- Department of Inorganic and Analytical Chemistry, BME Lendület Chemical Nanosensor Research GroupBudapest University of Technology and Economics Szt. Gellert tér 4 H-1111 Budapest Hungary
| |
Collapse
|
21
|
Kalinichev AV, Solovyeva EV, Ivanova AR, Khripoun GA, Mikhelson KN. Non-constancy of the bulk resistance of ionophore-based Cd2+-selective electrode: A correlation with the water uptake by the electrode membrane. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2019.135541] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
22
|
Shao Y, Ying Y, Ping J. Recent advances in solid-contact ion-selective electrodes: functional materials, transduction mechanisms, and development trends. Chem Soc Rev 2020; 49:4405-4465. [DOI: 10.1039/c9cs00587k] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This article presents a comprehensive overview of recent progress in the design and applications of solid-contact ion-selective electrodes (SC-ISEs).
Collapse
Affiliation(s)
- Yuzhou Shao
- Laboratory of Agricultural Information Intelligent Sensing
- School of Biosystems Engineering and Food Science
- Zhejiang University
- Hangzhou
- China
| | - Yibin Ying
- Laboratory of Agricultural Information Intelligent Sensing
- School of Biosystems Engineering and Food Science
- Zhejiang University
- Hangzhou
- China
| | - Jianfeng Ping
- Laboratory of Agricultural Information Intelligent Sensing
- School of Biosystems Engineering and Food Science
- Zhejiang University
- Hangzhou
- China
| |
Collapse
|
23
|
Baranowska-Korczyc A, Jaworska E, Strawski M, Paterczyk B, Maksymiuk K, Michalska A. A potentiometric sensor based on modified electrospun PVDF nanofibers – towards 2D ion-selective membranes. Analyst 2020; 145:5594-5602. [DOI: 10.1039/d0an00830c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Core–shell modified nanofiber mats were used as ion-selective membranes for the first time.
Collapse
Affiliation(s)
| | - Ewa Jaworska
- Faculty of Chemistry
- University of Warsaw
- 02-093 Warsaw
- Poland
| | | | - Bohdan Paterczyk
- Laboratory of Electron and Confocal Microscopy
- Faculty of Biology
- University of Warsaw
- 02-096 Warsaw
- Poland
| | | | | |
Collapse
|
24
|
Kondratyeva YO, Solovyeva EV, Khripoun GA, Mikhelson KN. Paradox of the Variation of the Bulk Resistance of Potassium Ion-Selective Electrode Membranes within Nernstian Potentiometric Response Range. RUSS J ELECTROCHEM+ 2019. [DOI: 10.1134/s1023193519110090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
25
|
Urbanowicz M, Pijanowska DG, Jasiński A, Ekman M, Bocheńska MK. A miniaturized solid-contact potentiometric multisensor platform for determination of ionic profiles in human saliva. J Solid State Electrochem 2019. [DOI: 10.1007/s10008-019-04429-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Abstract
This paper describes a miniaturized multisensor platform (MP-ISES) consisting of electrodes: a reference one (RE) and ion-selective electrodes (ISEs) for monitoring Na+, K+, Ca2+, Mg2+, Cl−, and SCN− ions and pH in human saliva. Gold electrode surface was modified by deposition of two layers: electrosynthesized PEDOT:PSS forming an intermediate layer, and ion-selective membrane. The developed ISEs were characterized by a wide linear range and sensitivity consistent with the Nernst model. The entire MP-ISEs are characterized by satisfactory metrological parameters demonstrating their applicability in biomedical research, in particular in measurements concerning determination of ionic profiles of saliva. Saliva samples of 18 volunteers aged from 20 to 26 participating in a month experiment had been daily collected and investigated using the MP-ISEs assigned individually to each person. Personalized profiles of ions (ionograms) in saliva, such as Na+, K+, Ca2+, Mg2+, Cl−, SCN−, and H+, were obtained.
Collapse
|
26
|
Joon NK, He N, Ruzgas T, Bobacka J, Lisak G. PVC-Based Ion-Selective Electrodes with a Silicone Rubber Outer Coating with Improved Analytical Performance. Anal Chem 2019; 91:10524-10531. [DOI: 10.1021/acs.analchem.9b01490] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Narender Kumar Joon
- Åbo Akademi University, Johan Gadolin Process Chemistry Centre, Laboratory of Analytical Chemistry, Biskopsgatan 8, FI-20500 Turku/Åbo, Finland
| | - Ning He
- Åbo Akademi University, Johan Gadolin Process Chemistry Centre, Laboratory of Analytical Chemistry, Biskopsgatan 8, FI-20500 Turku/Åbo, Finland
| | - Tautgirdas Ruzgas
- Department of Biomedical Science, Faculty of Health and Society, 205 06 Malmö, Sweden; Biofilms - Research Center for Biointerfaces, Malmö University, 214 32 Malmö, Sweden
| | - Johan Bobacka
- Åbo Akademi University, Johan Gadolin Process Chemistry Centre, Laboratory of Analytical Chemistry, Biskopsgatan 8, FI-20500 Turku/Åbo, Finland
| | - Grzegorz Lisak
- College of Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Nanyang Environment and Water Research Institute, 1 Cleantech Loop, CleanTech, Singapore 637141, Singapore
| |
Collapse
|
27
|
Papp S, Bojtár M, Gyurcsányi RE, Lindfors T. Potential Reproducibility of Potassium-Selective Electrodes Having Perfluorinated Alkanoate Side Chain Functionalized Poly(3,4-ethylenedioxytiophene) as a Hydrophobic Solid Contact. Anal Chem 2019; 91:9111-9118. [PMID: 31184105 PMCID: PMC6750645 DOI: 10.1021/acs.analchem.9b01587] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The irreproducibility of the standard potential (E°) is probably the last major challenge for the commercialization of solid-contact ion-selective electrodes (SCISEs) as single-use or wearable sensors. To overcome this issue, we are introducing for the first time a perfluorinated alkanoate side chain functionalized poly(3,4-ethylenedioxythiophene) (PEDOTF) as a hydrophobic SC in potassium-selective electrodes (K-SCISEs) based on plasticized poly(vinyl chloride). The SC incorporates the tetrakis(pentafluorophenyl)borate (TFAB-) anion, which is also present as a lipophilic additive in the ion-selective membrane (ISM), thus ensuring thermodynamic reversibility at the SC/ISM interface and improving the potential reproducibility of the electrodes. We show here that the PEDOTF-TFAB solid contact, which was prepolarized prior to the ISM deposition to either its half or fully conducting form (i.e. different oxidation states) in acetonitrile containing 0.01 M KTFAB, had a very stable open-circuit potential and an outstanding potential reproducibility of only ±0.5 mV (n = 6) for 1 h in the same solution after the prepolarization. This shows that the oxidation state of the highly hydrophobic PEDOTF-TFAB film (water contact angle 133°) is stable over time and can be precisely controlled with prepolarization. The SC was also not light sensitive, which is normally a disadvantage of conducting polymer SCs. After the ISM deposition, the standard deviation of the E° of the K-SCISEs prepared on glassy carbon was ±3.0 mV (n = 5), which is the same as that for conventional liquid contact K-ISEs. This indicates that the ISM deposition is the main source for the potential irreproducibility of the K-SCISEs, which has been overlooked previously.
Collapse
Affiliation(s)
- Soma Papp
- Department of Inorganic and Analytical Chemistry, Chemical Nanosensor Research Group , Budapest University of Technology and Economics , Szt. Gellért tér 4 , H-1111 Budapest , Hungary
| | - Márton Bojtár
- Chemical Biology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences , Hungarian Academy of Sciences , Magyar tudósok krt. 2 , H-1117 Budapest , Hungary
| | - Róbert E Gyurcsányi
- Department of Inorganic and Analytical Chemistry, Chemical Nanosensor Research Group , Budapest University of Technology and Economics , Szt. Gellért tér 4 , H-1111 Budapest , Hungary
| | - Tom Lindfors
- Åbo Akademi University , Faculty of Science and Engineering, Laboratory of Analytical Chemistry , Biskopsgatan 8 , FIN-20500 Åbo , Finland
| |
Collapse
|
28
|
|
29
|
Kondratyeva YO, Solovyeva EV, Khripoun GA, Mikhelson KN. Non-constancy of the bulk resistance of ionophore-based ion-selective electrode: A result of electrolyte co-extraction or of something else? Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2017.10.176] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
30
|
Nguyen Huynh NM, Boeva ZA, Smått JH, Pesonen M, Lindfors T. Reduced graphene oxide as a water, carbon dioxide and oxygen barrier in plasticized poly(vinyl chloride) films. RSC Adv 2018; 8:17645-17655. [PMID: 35542063 PMCID: PMC9080506 DOI: 10.1039/c8ra03080d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 04/30/2018] [Indexed: 12/28/2022] Open
Abstract
Herein, we report the incorporation of a 10 μm thick reduced graphene oxide (RGO) barrier layer in a plasticized poly(vinyl chloride) (PVC) film as the main constituent in ion-selective membranes used in potentiometric solid-contact ion-selective electrodes (SCISE). Fourier transform infrared attenuated total reflection (FTIR-ATR) and oxygen transmission rate (OTR) measurements showed that the embedded RGO barrier efficiently impedes the diffusion of liquid water, carbon dioxide and oxygen (O2) through the 400 μm thick PVC film, which causes potential instability and irreproducibility of the SCISEs. The measurements revealed that the RGO layer completely blocks the carbon dioxide diffusion, while it fully blocks the water diffusion for 16 h and reduced the OTR by 85% on average. The μm-thick RGO films used in this study were easier to handle and incorporate into host polymers, and form more efficient and robust barriers compared to the mono-, few- and multilayer graphene commonly applied as barrier layers for liquids and gases. We also demonstrated that the FTIR-ATR technique employed in the permeability measurements is a versatile and very sensitive technique for studying the diffusion of small amounts of water and carbon dioxide through graphene-based thin films. A 10 μm-thick reduced graphene oxide barrier layer efficiently blocks water, carbon dioxide and oxygen diffusion through plasticized PVC.![]()
Collapse
Affiliation(s)
- Ngoc Minh Nguyen Huynh
- Åbo Akademi University
- Faculty of Science and Engineering
- Laboratory of Analytical Chemistry
- (Johan Gadolin Process Chemistry Centre, PCC)
- 20500 Åbo
| | - Zhanna A. Boeva
- Åbo Akademi University
- Faculty of Science and Engineering
- Laboratory of Analytical Chemistry
- (Johan Gadolin Process Chemistry Centre, PCC)
- 20500 Åbo
| | - Jan-Henrik Smått
- Åbo Akademi University
- Faculty of Science and Engineering
- Laboratory of Physical Chemistry (Center for Functional Materials, FUNMAT)
- 20500 Åbo
- Finland
| | - Markus Pesonen
- Åbo Akademi University
- Faculty of Science and Engineering
- Physics (Center for Functional Materials, FUNMAT)
- 20500 Åbo
- Finland
| | - Tom Lindfors
- Åbo Akademi University
- Faculty of Science and Engineering
- Laboratory of Analytical Chemistry
- (Johan Gadolin Process Chemistry Centre, PCC)
- 20500 Åbo
| |
Collapse
|
31
|
Aki S, Sueyoshi K, Hisamoto H, Endo T. Origin of the Optical Response of a Dye-doped Plasticized Poly(vinyl chloride)-based Photonic Crystal Ion Sensor. ANAL SCI 2017; 33:1247-1251. [PMID: 29129863 DOI: 10.2116/analsci.33.1247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We investigated the origin of the optical responses of a two-dimensional photonic crystal (2D-PhC) optode membrane ion sensor based on plasticized poly(vinyl chloride) (PVC) containing lipophilic dye. We previously developed a highly sensitive potassium ion sensor. However, the contributions of various factors to the sensor's optical response could not be distinguished. Here, we synthesized a lipophilic dye with spectral changes that do not overlap with those of propagated light in the PhC. Using this synthesized dye excluded the contribution of light absorption by the dye to the peak intensity change of the ion sensor. In refractive index standard solutions, the bulk refractive index change upon ion extraction contributed negligibly. The contribution of diffracted light scattering by optical transparency change of the plasticized PVC upon ion extraction accounted for approximately 45% of the ion sensor's total response. These findings are important for the development of highly sensitive plasticized PVC-based 2D-PhC ion sensors.
Collapse
Affiliation(s)
- Shoma Aki
- Department of Applied Chemistry, Osaka Prefecture University
| | - Kenji Sueyoshi
- Department of Applied Chemistry, Osaka Prefecture University
| | | | - Tatsuro Endo
- Department of Applied Chemistry, Osaka Prefecture University.,PRESTO, Japan Science and Technology Agency
| |
Collapse
|
32
|
Guzinski M, Jarvis JM, Perez F, Pendley BD, Lindner E, De Marco R, Crespo GA, Acres RG, Walker R, Bishop J. PEDOT(PSS) as Solid Contact for Ion-Selective Electrodes: The Influence of the PEDOT(PSS) Film Thickness on the Equilibration Times. Anal Chem 2017; 89:3508-3516. [DOI: 10.1021/acs.analchem.6b04625] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Marcin Guzinski
- Department
of Biomedical Engineering, University of Memphis, Memphis, Tennessee 38152, United States
| | - Jennifer M. Jarvis
- Department
of Biomedical Engineering, University of Memphis, Memphis, Tennessee 38152, United States
| | - Felio Perez
- Material
Science Lab, Integrated Microscopy Center, University of Memphis, Memphis, Tennessee 38152, United States
| | - Bradford D. Pendley
- Department
of Biomedical Engineering, University of Memphis, Memphis, Tennessee 38152, United States
| | - Ernő Lindner
- Department
of Biomedical Engineering, University of Memphis, Memphis, Tennessee 38152, United States
| | - Roland De Marco
- Faculty
of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy
Downs, Queensland 4556, Australia
- School
of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
- Department
of Chemistry, Curtin University, GPO Box U1987, Perth, Western
Australia 6109, Australia
| | - Gaston A. Crespo
- Department
of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet
30, CH-1211 Geneva, Switzerland
| | - Robert G. Acres
- Australian Synchrotron, 800 Blackburn
Road, Clayton, Victoria 3168, Australia
| | - Raymart Walker
- Faculty
of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy
Downs, Queensland 4556, Australia
| | - Josiah Bishop
- Faculty
of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy
Downs, Queensland 4556, Australia
| |
Collapse
|
33
|
He N, Papp S, Lindfors T, Höfler L, Latonen RM, Gyurcsányi RE. Pre-Polarized Hydrophobic Conducting Polymer Solid-Contact Ion-Selective Electrodes with Improved Potential Reproducibility. Anal Chem 2017; 89:2598-2605. [DOI: 10.1021/acs.analchem.6b04885] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ning He
- Åbo Akademi University, Johan Gadolin Process
Chemistry Centre, Faculty of Science and Engineering, Laboratory of
Analytical Chemistry, Biskopsgatan 8, FIN-20500 Turku/Åbo, Finland
| | - Soma Papp
- Department
of Inorganic and Analytical Chemistry, MTA-BME “Lendület”
Chemical Nanosensors Research Group, Budapest University of Technology and Economics, Szt. Gellért tér 4, 1111 Budapest, Hungary
| | - Tom Lindfors
- Åbo Akademi University, Johan Gadolin Process
Chemistry Centre, Faculty of Science and Engineering, Laboratory of
Analytical Chemistry, Biskopsgatan 8, FIN-20500 Turku/Åbo, Finland
| | - Lajos Höfler
- Department
of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellért tér 4, H-1111 Budapest, Hungary
| | - Rose-Marie Latonen
- Åbo Akademi University, Johan Gadolin Process
Chemistry Centre, Faculty of Science and Engineering, Laboratory of
Analytical Chemistry, Biskopsgatan 8, FIN-20500 Turku/Åbo, Finland
| | - Róbert E. Gyurcsányi
- Department
of Inorganic and Analytical Chemistry, MTA-BME “Lendület”
Chemical Nanosensors Research Group, Budapest University of Technology and Economics, Szt. Gellért tér 4, 1111 Budapest, Hungary
| |
Collapse
|
34
|
An Q, Jiao L, Jia F, Ye J, Li F, Gan S, Zhang Q, Ivaska A, Niu L. Robust single-piece all-solid-state potassium-selective electrode with monolayer-protected Au clusters. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2016.10.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
35
|
Solid contact ion sensor with conducting polymer layer copolymerized with the ion-selective membrane for determination of calcium in blood serum. Anal Chim Acta 2016; 943:50-57. [PMID: 27769376 DOI: 10.1016/j.aca.2016.09.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 01/14/2023]
Abstract
A new solid contact ion selective electrode with intermediate conducting polymer (CP) layer formed by electropolymerization on a gold electrode of a bifunctional monomer, n-phenyl-ethylenediamine-methacrylamide (NPEDMA), which contains a methacrylamide group attached to aniline, is presented. The conducting polymer was studied by means of optical spectroscopy, cyclic voltammetry and potentiometric measurements. Ca2+-ion-selective membrane based on acrylated urethane polymer was shown to co-polymerize with the CP forming highly adhesive boundary that prevents formation of water layers between the CP and membrane, thus enhancing the stability and life-time of the sensor. The designed ion-selective electrode was successfully used for determination of total calcium ion concentration in blood serum samples.
Collapse
|
36
|
Antonio JL, Höfler L, Lindfors T, Córdoba de Torresi SI. Electrocontrolled Swelling and Water Uptake of a Three-Dimensional Conducting Polypyrrole Hydrogel. ChemElectroChem 2016. [DOI: 10.1002/celc.201600397] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Jadielson L. Antonio
- Instituto de Química; Universidade de São Paulo. C.P.; 26077.05513-970 São Paulo Brazil
| | - Lajos Höfler
- Department of Inorganic and Analytical Chemistry; Budapest University of Technology and Economics; Szt. Gellért tér 4 H-1111 Budapest Hungary
| | - Tom Lindfors
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University, Faculty of Science and Engineering, Laboratory of Analytical Chemistry; Biskopsgatan 8 FIN-20500 Turku Finland
| | | |
Collapse
|
37
|
Hu J, Stein A, Bühlmann P. Rational design of all-solid-state ion-selective electrodes and reference electrodes. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2015.11.004] [Citation(s) in RCA: 220] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
38
|
He N, Gyurcsányi RE, Lindfors T. Electropolymerized hydrophobic polyazulene as solid-contacts in potassium-selective electrodes. Analyst 2016; 141:2990-7. [DOI: 10.1039/c5an02664d] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electropolymerized hydrophobic polyazulene based solid-contact potassium-selective electrodes have been characterized in terms of their suitability for potassium measurements in serum.
Collapse
Affiliation(s)
- Ning He
- Åbo Akademi University
- Faculty of Science and Engineering
- Johan Gadolin Process Chemistry Centre
- Laboratory of Analytical Chemistry
- FIN-20500 Turku/Åbo
| | - Róbert E. Gyurcsányi
- MTA-BME “Lendület” Chemical Nanosensors Research Group
- Department of Inorganic and Analytical Chemistry
- Budapest University of Technology and Economics
- Budapest
- Hungary
| | - Tom Lindfors
- Åbo Akademi University
- Faculty of Science and Engineering
- Johan Gadolin Process Chemistry Centre
- Laboratory of Analytical Chemistry
- FIN-20500 Turku/Åbo
| |
Collapse
|
39
|
Szűcs J, Lindfors T, Bobacka J, Gyurcsányi RE. Ion-selective Electrodes with 3D Nanostructured Conducting Polymer Solid Contact. ELECTROANAL 2015. [DOI: 10.1002/elan.201500465] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
40
|
|
41
|
Sohail M, De Marco R, Jarolímová Z, Pawlak M, Bakker E, He N, Latonen RM, Lindfors T, Bobacka J. Transportation and Accumulation of Redox Active Species at the Buried Interfaces of Plasticized Membrane Electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:10599-10609. [PMID: 26327251 DOI: 10.1021/acs.langmuir.5b01693] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The transportation and accumulation of redox active species at the buried interface between glassy carbon electrodes and plasticized polymeric membranes have been studied using synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS), near edge X-ray absorption fine structure (NEXAFS), in situ electrochemical Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy, cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). Ferrocene tagged poly(vinyl chloride) [FcPVC], ferrocene (Fc), and its derivatives together with tetracyanoquinodimethane (TCNQ) doped plasticized polymeric membrane electrodes have been investigated, so as to extend the study of the mechanism of this reaction chemistry to different time scales (both small and large molecules with variable diffusion coefficients) using a range of complementary electrochemical and surface analysis techniques. This study also provides direct spectroscopic evidence for the transportation and electrochemical reactivity of redox active species, regardless of the size of the electrochemically reactive molecule, at the buried interface of the substrate electrode. With all redox dopants, when CA electrolysis was performed, redox active species were undetectable (<1 wt % of signature elements or below the detection limit of SR-XPS and NEXAFS) in the outermost surface layers of the membrane, while a high concentration of redox species was located at the electrode substrate as a consequence of the deposition of the reaction product (Fc(+)-anion complex) at the buried interface between the electrode and the membrane. This reaction chemistry for redox active species within plasticized polymeric membranes may be useful in the fashioning of multilayered polymeric devices (e.g., chemical sensors, organic electronic devices, protective laminates, etc.) based on an electrochemical tunable deposition of redox molecules at the buried substrate electrode beneath the membrane.
Collapse
Affiliation(s)
- Manzar Sohail
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast , 90 Sippy Downs Drive, Sippy Downs, Queensland 4556, Australia
| | - Roland De Marco
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast , 90 Sippy Downs Drive, Sippy Downs, Queensland 4556, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, Queensland 4072, Australia
- Department of Chemistry, Curtin University , GPO Box U1987, Perth, Western Australia 6109, Australia
| | - Zdeňka Jarolímová
- Department of Inorganic and Analytical Chemistry, University of Geneva , Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Marcin Pawlak
- Department of Inorganic and Analytical Chemistry, University of Geneva , Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Eric Bakker
- Department of Inorganic and Analytical Chemistry, University of Geneva , Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Ning He
- Johan Gadolin Process Chemistry Centre, c/o Laboratory of Analytical Chemistry, Åbo Akademi University , Biskopsgatan 8, FI-20500 Turku-Åbo, Finland
| | - Rose-Marie Latonen
- Johan Gadolin Process Chemistry Centre, c/o Laboratory of Analytical Chemistry, Åbo Akademi University , Biskopsgatan 8, FI-20500 Turku-Åbo, Finland
| | - Tom Lindfors
- Johan Gadolin Process Chemistry Centre, c/o Laboratory of Analytical Chemistry, Åbo Akademi University , Biskopsgatan 8, FI-20500 Turku-Åbo, Finland
| | - Johan Bobacka
- Johan Gadolin Process Chemistry Centre, c/o Laboratory of Analytical Chemistry, Åbo Akademi University , Biskopsgatan 8, FI-20500 Turku-Åbo, Finland
| |
Collapse
|
42
|
Guzinski M, Jarvis JM, Pendley BD, Lindner E. Equilibration Time of Solid Contact Ion-Selective Electrodes. Anal Chem 2015; 87:6654-9. [DOI: 10.1021/acs.analchem.5b00775] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Marcin Guzinski
- Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee, United States
| | - Jennifer M. Jarvis
- Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee, United States
| | - Bradford D. Pendley
- Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee, United States
| | - Ernő Lindner
- Department of Biomedical Engineering, The University of Memphis, Memphis, Tennessee, United States
| |
Collapse
|
43
|
Potential Cycling Stability of Composite Films of Graphene Derivatives and Poly(3,4-ethylenedioxythiophene). ELECTROANAL 2015. [DOI: 10.1002/elan.201400572] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
44
|
Ivanova NM, Levin MB, Mikhelson KN. Problems and prospects of solid contact ion-selective electrodes with ionophore-based membranes. Russ Chem Bull 2013. [DOI: 10.1007/s11172-012-0136-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
45
|
He N, Lindfors T. Determination of Water Uptake of Polymeric Ion-Selective Membranes with the Coulometric Karl Fischer and FT-IR-Attenuated Total Reflection Techniques. Anal Chem 2012; 85:1006-12. [DOI: 10.1021/ac3027838] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ning He
- Åbo Akademi University, Process Chemistry Centre, Laboratory of
Analytical Chemistry, Biskopsgatan 8, FIN-20500 Turku/Åbo, Finland
- The Graduate School of Chemical
Sensors and Microanalytical Systems, CHEMSEM, Finland
| | - Tom Lindfors
- Åbo Akademi University, Process Chemistry Centre, Laboratory of
Analytical Chemistry, Biskopsgatan 8, FIN-20500 Turku/Åbo, Finland
- Academy of Finland, Helsinki, Finland
| |
Collapse
|
46
|
Lai H, Wang Z, Wu P, Chaudhary BI, Sengupta SS, Cogen JM, Li B. Structure and Diffusion Behavior of Trioctyl Trimellitate (TOTM) in PVC Film Studied by ATR-IR Spectroscopy. Ind Eng Chem Res 2012. [DOI: 10.1021/ie300007m] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hengjie Lai
- The State Key Laboratory
of
Molecular Engineering of Polymers and Department of Macromolecular
Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, P.R.China
| | - Zhangwei Wang
- The State Key Laboratory
of
Molecular Engineering of Polymers and Department of Macromolecular
Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, P.R.China
| | - Peiyi Wu
- The State Key Laboratory
of
Molecular Engineering of Polymers and Department of Macromolecular
Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, P.R.China
| | - Bharat Indu Chaudhary
- The Dow Chemical Company, 727 Norristown Road, Spring House, Pennsylvania
19477, United States
| | - Saurav S Sengupta
- The Dow Chemical Company, 727 Norristown Road, Spring House, Pennsylvania
19477, United States
| | - Jeffrey M Cogen
- The Dow Chemical Company, 727 Norristown Road, Spring House, Pennsylvania
19477, United States
| | - Bin Li
- Dow Chem (China) Co. Ltd., 3D217, Shanghai Dow Center, 936 Zhang Heng
Road, Shanghai 201203, P.R.China
| |
Collapse
|
47
|
Anion selectivity at the aqueous/polymeric membrane interface: A streaming current study of potentiometric Hofmeister effect. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.03.113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
48
|
Veder JP, Patel K, Sohail M, Jiang SP, James M, De Marco R. An Electrochemical Impedance Spectroscopy/Neutron Reflectometry Study of Water Uptake in the Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate)/Polymethyl Methacrylate-Polydecyl Methacrylate Copolymer Solid-Contact Ion-Selective Electrode. ELECTROANAL 2011. [DOI: 10.1002/elan.201100524] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
49
|
Lindfors T, Sundfors F, Höfler L, Gyurcsányi RE. The Water Uptake of Plasticized Poly(vinyl chloride) Solid-Contact Calcium-Selective Electrodes. ELECTROANAL 2011. [DOI: 10.1002/elan.201100219] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
50
|
Pejcic B, Crooke E, Doherty CM, Hill AJ, Myers M, Qi X, Ross A. The impact of water and hydrocarbon concentration on the sensitivity of a polymer-based quartz crystal microbalance sensor for organic compounds. Anal Chim Acta 2011; 703:70-9. [PMID: 21843677 DOI: 10.1016/j.aca.2011.07.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 07/06/2011] [Accepted: 07/10/2011] [Indexed: 10/18/2022]
Abstract
Long-term environmental monitoring of organic compounds in natural waters requires sensors that respond reproducibly and linearly over a wide concentration range, and do not degrade with time. Although polymer coated piezoelectric based sensors have been widely used to detect hydrocarbons in aqueous solution, very little information exists regarding their stability and suitability over extended periods in water. In this investigation, the influence of water aging on the response of various polymer membranes [polybutadiene (PB), polyisobutylene (PIB), polystyrene (PS), polystyrene-co-butadiene (PSB)] was studied using the quartz crystal microbalance (QCM). QCM measurements revealed a modest increase in sensitivity towards toluene for PB and PIB membranes at concentrations above 90 ppm after aging in water for 4 days. In contrast, the sensitivity of PS and PSB coated QCM sensors depended significantly on the toluene concentration and increased considerably at concentrations above 90 ppm after aging in water for 4 days. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) showed that there is a change in the sorption mechanism at higher toluene levels for PS and PSB. Positron annihilation lifetime spectroscopy (PALS) studies were performed to investigate the free volume properties of all polymers and to monitor any changes in the free volume size and distribution due to water and toluene exposure. The PALS did not detect any considerable variation in the free volume properties of the polymer films as a function of solution composition and soaking time, implying that viscoelastic and/or interfacial processes (i.e. surface area changes) are probably responsible for variations in the QCM sensitivity at high hydrocarbon concentrations. The results suggest that polymer membrane conditioning in water is an issue that needs to be considered when performing QCM measurements in the aqueous phase. In addition, the study shows that the hydrocarbon response is concentration dependant for polymers with a high glass transition temperature, and this feature is often neglected when comparing sensor sensitivity in the literature.
Collapse
Affiliation(s)
- Bobby Pejcic
- CSIRO, Earth Science and Resource Engineering, Bentley, WA, Australia.
| | | | | | | | | | | | | |
Collapse
|