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Ghanbari Ghalehjoughi N, Wang R, Kelley S, Wang X. Ultrasensitive Ionophore-Based Liquid Sensors for Colorimetric Ion Measurements in Blood. Anal Chem 2023; 95:12557-12564. [PMID: 37567148 DOI: 10.1021/acs.analchem.3c02926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2023]
Abstract
The self-monitoring of electrolytes using a small volume of capillary blood is needed for the management of many chronic diseases. Herein, we report an ionophore-based colorimetric sensor for electrolyte measurements in a few microliters of blood. The sensor is a pipet microtip preloaded with a segment of oil (plasticizer) containing a pH-sensitive chromoionophore, a cation exchanger, and an ionophore. The analyte is extracted from the sample into the oil via a mixing protocol controlled by a stepper motor. The oil with an optimized ratio of sensing chemicals shows an unprecedentedly large color response for electrolytes in a very narrow concentration range that is clinically relevant. This ultrahigh sensitivity is based on an exhaustive response mode with a novel mechanism for defining the lower and higher limits of detection. Compared to previous optodes and molecular probes for ions, the proposed platform is especially suitable for at-home blood electrolyte measurements because (1) the oil sensor is interrogated independent of the sample and therefore works for whole blood without requiring plasma separation; (2) the sensor does not need individual calibration as the consistency between liquid sensors is high compared to solid sensors, such as ion-selective electrodes and optodes; and (3) the sensing system consisting of a disposable oil sensor, a programmed stepper motor, and a smartphone is portable, cost-effective, and user-friendly. The accuracy and precision of Ca2+ sensors are validated in 51 blood samples with varying concentrations of total plasma Ca2+. Oil sensors with an ultrasensitive response can also be obtained for other ions, such as K+.
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Affiliation(s)
- Nasrin Ghanbari Ghalehjoughi
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main Street, Richmond, Virginia 23284, United States
| | - Renjie Wang
- Department of Chemistry and Biochemistry, Florida Atlantic University, 777 Glades Road, Boca Raton, Florida 33431, United States
| | - Savannah Kelley
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main Street, Richmond, Virginia 23284, United States
| | - Xuewei Wang
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main Street, Richmond, Virginia 23284, United States
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2
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Guo C, Zhai J, Chen Q, Du X, Xie X. Phase transfer of fatty acids into ultrasmall nanospheres for colorimetric detection of lipase and albumin. Chem Commun (Camb) 2022; 58:5037-5040. [PMID: 35377380 DOI: 10.1039/d2cc01089e] [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
Colorimetric detection of fatty acids during biological interactions is extremely difficult since they are optically silent. Here, fatty acids are found to function as ion-exchangers in ultrasmall polymeric nanospheres to facilitate the protonation of chromoionophores, causing a vivid color change between red and blue. With an excellent detection limit of 1.8 μg mL-1 for oleic acid, colorimetric assays for lipase and albumin are developed with quick response, high sensitivity, and low cost.
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Affiliation(s)
- Chao Guo
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Jingying Zhai
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Qinghan Chen
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Xinfeng Du
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Xiaojiang Xie
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
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3
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Robinson KJ, Soda Y, Bakker E. Recent improvements to the selectivity of extraction-based optical ion sensors. Chem Commun (Camb) 2022; 58:4279-4287. [PMID: 35201251 PMCID: PMC8972301 DOI: 10.1039/d1cc06636f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Optical sensors continue to demonstrate tremendous potential across a wide range of applications due to their high versatility and low cost. This feature article will focus on a number of recent advances made in improving the performance of extraction-based optical ion sensors within our group. This includes the progress of anchored solvatochromic transduction to provide pH and sample volume independent optical responses in nanoemulsion-based sensors. A recent breakthough is in polyion sensing in biological fluids that uses a novel indirect transduction mechanism that significantly improves the selectivity of dinonylnaphthalenesulfonate-based protamine sensors and its potential applications beyond polyion sensing. The role of particle stabilizers in relation to the response of emulsified sensors is shown to be important. Current challenges in the field and possible opportunities are also discussed. Selectivity remains a constant challenge in the development of optical extraction-based sensors. Fortunately, there are several mechanistic and compositional changes with the potential to improve selectivity without developing new ionophores.![]()
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Affiliation(s)
- Kye J Robinson
- Department of Inorganic, Analytical Chemistry University of Geneva Quai Ernest-Ansermet 30, 1211 Geneva, Switzerland.
| | - Yoshiki Soda
- Department of Inorganic, Analytical Chemistry University of Geneva Quai Ernest-Ansermet 30, 1211 Geneva, Switzerland.
| | - Eric Bakker
- Department of Inorganic, Analytical Chemistry University of Geneva Quai Ernest-Ansermet 30, 1211 Geneva, Switzerland.
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4
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Advances in Therapeutic Monitoring of Lithium in the Management of Bipolar Disorder. SENSORS 2022; 22:s22030736. [PMID: 35161482 PMCID: PMC8838674 DOI: 10.3390/s22030736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/08/2022] [Accepted: 01/12/2022] [Indexed: 11/16/2022]
Abstract
Since the mid-20th century, lithium continues to be prescribed as a first-line mood stabilizer for the management of bipolar disorder (BD). However, lithium has a very narrow therapeutic index, and it is crucial to carefully monitor lithium plasma levels as concentrations greater than 1.2 mmol/L are potentially toxic and can be fatal. The quantification of lithium in clinical laboratories is performed by atomic absorption spectrometry, flame emission photometry, or conventional ion-selective electrodes. All these techniques are cumbersome and require frequent blood tests with consequent discomfort which results in patients evading treatment. Furthermore, the current techniques for lithium monitoring require highly qualified personnel and expensive equipment; hence, it is crucial to develop low-cost and easy-to-use devices for decentralized monitoring of lithium. The current paper seeks to review the pertinent literature rigorously and critically with a focus on different lithium-monitoring techniques which could lead towards the development of automatic and point-of-care analytical devices for lithium determination.
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Wang R, Zhou Y, Ghanbari Ghalehjoughi N, Mawaldi Y, Wang X. Ion-Induced Phase Transfer of Cationic Dyes for Fluorescence-Based Electrolyte Sensing in Droplet Microfluidics. Anal Chem 2021; 93:13694-13702. [PMID: 34590485 DOI: 10.1021/acs.analchem.1c03394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluorescence-based sensing in droplet microfluidics requires small sample volumes, allows for high-throughput assays, and does not suffer from photobleaching as each flowing sensor is only scanned one time. In this paper, we report a selective and sensitive fluorescence-based ion-sensing methodology in droplet microfluidics using a T-junction PDMS chip. The oil stream is doped with sensor ingredients including an ionophore, a cation exchanger, and a permanently cationic fluorophore as the optical reporter. Electrolyte cations from the aqueous sample are extracted into oil segments and displace the cationic dyes into aqueous droplets. Laser-induced fluorescence of the two immiscible phases is collected alternately, which is in clear contrast to most other ion-selective optode configurations such as nanoparticle suspensions that rely on mixed optical signals of two phases. The cation exchanger, tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, is found to dramatically enhance the dye emission in the nonpolar sensing oil by preventing ion-pairing interactions and aggregations of the dye molecules, providing new insights into the mechanism of cationic dye-based ion sensors. The high dye brightness allows us to use low concentrations of sensing chemicals (e.g., 10 μM) in the oil and attain high sensitivity for detection of ions in an equal volume of sample. Using valinomycin as the ionophore and methylene blue as the dye, K+ is detected with a response time of ∼11 s, a logarithmic linear range of 10-5 to 10-2 M, a 20-fold total fluorescence response, >1000-fold selectivity against other electrolyte cations, and negligible cross-sensitivity toward the sample pH. The K+ concentration in untreated and undiluted whole blood and sweat samples is successfully determined by this microfluidic sensing method without optical interference from the droplet sample to the sensing oil. Detection of other ionic analytes can be achieved using the corresponding ionophores.
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Affiliation(s)
- Renjie Wang
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States
| | - Yang Zhou
- School of Chemical Engineering and Technology, Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228, China
| | | | - Yazan Mawaldi
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States
| | - Xuewei Wang
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States
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6
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A colorimetric paper-based optode sensor for highly sensitive and selective determination of thiocyanate in urine sample using cobalt porphyrin derivative. Talanta 2021; 231:122371. [PMID: 33965036 DOI: 10.1016/j.talanta.2021.122371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 12/27/2022]
Abstract
In this work, a highly sensitive colorimetric paper-based optode for the determination of thiocyanate in urine samples was developed for the first time. The cocktail solution of the optode was composed of 5,10,15,20-tetrakis(4-octyloxyphenyl)porphyrin cobalt(II) complex (L), tridodecylmethylammonium chloride (TDMACl), 2-nitrophenyl octyl ether, and polyvinyl chloride as an ionophore, an ion exchanger, a plasticizer, and a polymer, respectively. The paper-based optode responded to thiocyanate by increasing the blue component in the RGB index and a visible change, with the naked-eye, of the optode color from pink to green was observed. From the central composite design, the optimized conditions that yielded the highest sensitivity were 4.70 mmol/kg TDMACl and 13.75 mmol/kg L. The developed optode sensor was highly selective and responded to thiocyanate over other anions, with a working range of 0.001-5 mM and with a coefficient of determination (R2) of 0.9915. The limits of detection using naked-eye and camera were determined to be 50.0 μM and 1.26 μM, respectively. In addition, the LOD and LOQ estimated from the standard deviation of the blank were 0.65 and 1.87 μM, respectively. Furthermore, this sensor was successfully applied to the detection of thiocyanate in urine samples from non-smokers and smokers. The results were in good agreement with the standard ion chromatography (IC) technique. This developed paper-based optode sensor was simple, low-cost, portable, and easy to use as a sensing device without any complicated instrument.
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Zhao L, Luo F, Wang A, Zhang J, Wang Y, Zhao L, Wang Z, Pu Q. Quick stabilization of capillary for rapid determination of potassium ions in the blood of epilepsy patients by capillary electrophoresis without sample pretreatment. Electrophoresis 2020; 41:1273-1279. [PMID: 32358896 DOI: 10.1002/elps.202000022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 11/07/2022]
Abstract
Mutations in the potassium channel genes may be linked to the development of epilepsy and affect the blood potassium levels. Therefore, accurate determination of potassium in the blood will be critical to diagnose the cause of epilepsy. CE is a competent technique for the fast detection of multiple ions, but complicated matrices of a blood sample may cause significant variation of migration times and the peak shape. In this work, a procedure for rapid stabilization of the capillary inner surface through preflushing of a blood sample was employed. The process takes only 40 min for a capillary and then it can be used for more than 2 weeks. No pretreatment of the blood sample or other surface modification of the capillary is needed for the analysis. The RSDs of the migration time and peak area were reduced to 1.5 and 5.1% from 12.6 and 14.5%, respectively. The proposed method has been successfully applied to the determination of the potassium contents in the blood sample of patients with epilepsy at different stages. The recoveries of potassium ions in these blood samples are in a range from 86.5 to 104.5%.
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Affiliation(s)
- Litao Zhao
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Fanghong Luo
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Anting Wang
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Jing Zhang
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Yuanhang Wang
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China
| | - Liangtao Zhao
- TSing Biomedical Research Center, The Second Hospital of Lanzhou University, Lanzhou, P. R. China
| | - Zhaoyan Wang
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Qiaosheng Pu
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China
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9
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Akbarzadeh A, Zadmard R, Jalali MR. Synthesis of novel 6-piperidin-1-ylpyrimidine-2,4-diamine 3-oxide substituted calix[4]arene as a highly selective and sensitive fluorescent sensor for Cu2+ in aqueous samples. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.151658] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Vishaka HV, Saxena M, Chandan HR, Ojha AA, Balakrishna RG. Paper based field deployable sensor for naked eye monitoring of copper (II) ions; elucidation of binding mechanism by DFT studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 223:117291. [PMID: 31284241 DOI: 10.1016/j.saa.2019.117291] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/17/2019] [Accepted: 06/17/2019] [Indexed: 06/09/2023]
Abstract
The study demonstrates the fabrication of test strips made from newly synthesized ortho-Vanillin based colorimetric chemosensor (probe P) that could be employed as field deployable tool for rapid and naked eye detection of Cu2+. Upon addition of Cu2+ to the chemosensor, it exhibits rapid pink color from colorless and can be easily seen through the naked eye. This probe exhibits a remarkable colorimetric "ON" response and the absorbance intensity of the probe enhances significantly in presence of Cu2+. The sensing mechanism has been deduced using FTIR, XPS, LCMS and DFT studies. The binding mechanism of the probe to Cu2+ was substantiated by DFT studies. HOMO of the probe suggests that a high electronic density resides on O, N atoms and thus these are the favorable binding site for the metal ions. Study revealed that the P + Cu2+ complex is -35.64 eV more stable than individual reactants. The Cu2+ binds to the probe in 1:1 stoichiometry with a binding constant of 2.6 × 104 M-1 as calculated by Job's plot and Benesi-Hildebrand plot. The chemosensor shows 1.8 × 10-8 M detection limit, which is considerably lesser than that of the WHO admissible limit of [Cu2+] in drinking water. Possible interfering ions namely Ca2+, Mg2+, Fe2+, Co2+, Ni2+, Cd2+, Hg2+, Mn2+, Al3+ and Cr3+ do not show any appreciable interference in the colorimetric response of the probe towards Cu2+. Particularly, the colorimetric "ON-OFF-ON" responses are proved to be repeated over 5 times by the sequential inclusion of Cu2+ and S2-. Sensitivity of the probe in real-time water and blood samples is found at par with results with AAS and ICP-OES techniques. Further, the reversibility of the probe and the easy fabrication of deployable strips for real-field naked eye detection of Cu2+ suggest importance of synthesized probe.
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Affiliation(s)
- Halali V Vishaka
- Centre for Nano and Material Sciences, Jain University, Ramanagaram, Bangalore 562112, India
| | - Manav Saxena
- Centre for Nano and Material Sciences, Jain University, Ramanagaram, Bangalore 562112, India
| | - H R Chandan
- Centre for Nano and Material Sciences, Jain University, Ramanagaram, Bangalore 562112, India
| | | | - R Geetha Balakrishna
- Centre for Nano and Material Sciences, Jain University, Ramanagaram, Bangalore 562112, India.
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11
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Sirbu D, Zeng L, Waddell PG, Benniston AC. An unprecedented oxidised julolidine-BODIPY conjugate and its application in real-time ratiometric fluorescence sensing of sulfite. Org Biomol Chem 2019; 17:7360-7368. [PMID: 31339165 DOI: 10.1039/c9ob01316d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Reaction of a julolidine-based BODIPY compound with silver(i) ions in the presence of white light produced the oxidised julolidine version (OXJUL) containing a quaternary nitrogen. The oxidation of one ring at the julolidine site is highly unusual and there is no other reported literature example. The fluorescence maximum of OXJUL is altered from 648 nm to 608 nm by the addition of an aqueous solution of Na2SO3 over several minutes. In the presence of a large excess of sulfite a further slower reaction is observed which further shifts the emission maximum to 544 nm. The alterations form the basis of a real-time ratiometric sensor for sulfite and its detection in a white wine.
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Affiliation(s)
- D Sirbu
- Molecular Photonics Laboratory, Chemistry-School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
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12
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Affiliation(s)
- Li Deng
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jingying Zhai
- SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xiaojiang Xie
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
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13
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Zdrachek E, Bakker E. From Molecular and Emulsified Ion Sensors to Membrane Electrodes: Molecular and Mechanistic Sensor Design. Acc Chem Res 2019; 52:1400-1408. [PMID: 31017760 DOI: 10.1021/acs.accounts.9b00056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Selective molecular ion probes are often insoluble in water and require a hydrophobic solvent environment for strong and selective binding, which runs counter to the desire of utilizing them in a homogeneous solution. This Account aims to guide the reader on how such molecules, often coined ionophores, can be harnessed to design exceptionally useful optical and electrochemical sensors. We start here with some historical context on the design of such ionophores and continue with the explanation of the response mechanism of optical and potentiometric sensors and the role of combined components to build a robust ion sensor. This Account is addressed to nonspecialist readers and for this reason avoids extensive use of equations or theoretical considerations. The interested reader should turn to the original literature for further reading. Emulsified optical sensors are introduced as an initial example. Here, multiple reagents are confined in an attoliter sensing nanodroplet of the organic phase, immiscible with the aqueous sample phase. In this case, the ionophore molecules may retain their high affinity and selectivity to the target ion and the aqueous sample phase does not have to be modified. Emulsified optical sensors allow one to achieve the selective chemical sensing of ions, even with optically silent ionophores. Such ionophore-based nanodroplets are also discussed as a useful novel class of complexometric titration reagents and optical end point indicators with unique selectivities. We then turn our attention to potentiometric sensing probes and briefly discuss the unique opportunity of a direct characterization of ion-ionophore complexation properties offered by membrane electrodes. A carbonate-selective membrane electrode containing a highly selective tweezer-type ionophore with trifluoroacetophenone functional groups is then used as an example for the construction of a robust all-solid-state sensor. This potentiometric probe, in combination with a pH electrode, can directly measure PCO2 in freshwater lakes, demonstrating a dramatically improved response time relative to traditional sensors equipped with a gas-permeable membrane. In recent years, new sensing modes and electrode designs have been introduced to expand the application scope of ionophore-based potentiometric sensors. Membrane electrodes containing ionophores are placed under dynamic electrochemistry control to give important progress in the field. We specifically highlight our recent works by membranes that are controlled by chronopotentiometry (controlled current) for speciation analysis, by ion transfer voltammetry on thin sensing films for multianalyte detection, by exhaustive coulometry for potentially calibration-free sensors and with coulometric membrane pumps for the selective delivery of reagents.
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Affiliation(s)
- Elena Zdrachek
- University of Geneva, Department of Inorganic and Analytical Chemistry, Quai Ernest Ansermet 30, Geneva 1211, Switzerland
| | - Eric Bakker
- University of Geneva, Department of Inorganic and Analytical Chemistry, Quai Ernest Ansermet 30, Geneva 1211, Switzerland
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14
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Du X, Huang M, Wang R, Zhai J, Xie X. A rapid point-of-care optical ion sensing platform based on target-induced dye release from smart hydrogels. Chem Commun (Camb) 2019; 55:1774-1777. [DOI: 10.1039/c8cc09434a] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We report here a rapid and versatile metal ion analytical platform based on the dye release from hydrogels entrapping ion-selective microdroplets.
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Affiliation(s)
- Xinfeng Du
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- China
| | - Manling Huang
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- China
| | - Renjie Wang
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- China
| | - Jingying Zhai
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- China
| | - Xiaojiang Xie
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- China
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15
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Abstract
Food fraud can be highly lucrative, and high accuracy authentication of various foodstuffs is becoming essential. Olive oil is one of the most investigated food matrices, due to its high price and low production globally, with recent food fraud examples showing little or no high quality olive oil in the tested oils. Here a simple method using a 405 nm LED flashlight and a smartphone is developed for edible oil authentication. Identification is fingerprinted by intrinsic fluorescent compounds in the oils, such as chlorophylls and polyphenols. This study uses the hue parameter of HSV-colorspace to authenticate 24 different edible oils of 9 different types and 15 different brands. For extra virgin olive oil, all nine samples are well separated from the other oil samples. The rest of the samples were also well type-distinguished by the hue parameter, which is complemented by hue-histogram analysis. This opens up opportunities for low-cost and high-throughput smartphone field-testing of edible oils on all levels of the production and supply chain.
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Affiliation(s)
- Aron Hakonen
- Sensor Visions AB, Legendgatan 116, 422 55 Hisings Backa, Sweden
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16
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Thajee K, Wang L, Grudpan K, Bakker E. Colorimetric ionophore-based coextraction titrimetry of potassium ions. Anal Chim Acta 2018; 1029:37-43. [PMID: 29907288 DOI: 10.1016/j.aca.2018.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 12/29/2022]
Abstract
Potassium ion concentration can be successfully determined volumetrically by moving the titration from a homogeneous phase to a two phase solvent system. This is because potassium can be readily complexed in a selective and thermodynamically stable manner by ionophores such as valinomycin. Previous work demonstrated the successful titration of potassium by ion-exchange into an organic phase containing valinomycin, but the sample itself served as titrant, which is not sufficiently practical for routine applications. This problem is overcome here by a co-extraction based approach, with the sodium salt of the water soluble lipophilic anion tetraphenylborate as titrant. The extraction of potassium tetraphenylborate must be preferred over that of the hydrogen ion-tetraphenylborate pair, which is used to indicate the endpoint by the presence of a lipophilic indicator in the organic phase. This is controlled by the sample pH, which for the conditions chosen here is around 7 for optimal sharpness and accuracy of the endpoint. The approach is demonstrated in a colorimetric detection approach, by use of a tethered digital camera and subsequent automated analysis of the resulting image files. The potassium analysis in a variety of samples is successfully demonstrated, including blood serum.
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Affiliation(s)
- Kajorngai Thajee
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland; Center of Excellence for Innovation in Analytical Science and Technology, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Lu Wang
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland
| | - Kate Grudpan
- Center of Excellence for Innovation in Analytical Science and Technology, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Eric Bakker
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
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Du X, Yang L, Hu W, Wang R, Zhai J, Xie X. A Plasticizer-Free Miniaturized Optical Ion Sensing Platform with Ionophores and Silicon-Based Particles. Anal Chem 2018; 90:5818-5824. [DOI: 10.1021/acs.analchem.8b00360] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Xinfeng Du
- Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China
| | - Liyuan Yang
- Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China
| | - WenChang Hu
- Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China
| | - Renjie Wang
- Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China
| | - Jingying Zhai
- Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China
| | - Xiaojiang Xie
- Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China
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18
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Affiliation(s)
- Jingying Zhai
- Department of Chemistry; Southern University of Science and Technology; Shenzhen P. R. China
| | - Changyou Zhu
- Department of Chemistry; Southern University of Science and Technology; Shenzhen P. R. China
| | - Xinlei Peng
- Department of Chemistry; Southern University of Science and Technology; Shenzhen P. R. China
| | - Xiaojiang Xie
- Department of Chemistry; Southern University of Science and Technology; Shenzhen P. R. China
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19
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Du X, Xie X. Non-Equilibrium Diffusion Controlled Ion-Selective Optical Sensor for Blood Potassium Determination. ACS Sens 2017; 2:1410-1414. [PMID: 28949507 DOI: 10.1021/acssensors.7b00614] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Blood electrolyte measurements play important roles in clinical diagnostics. Optical ion sensors as simple and elegant as a mercury thermometer are in high demand. We present here an analytical method to quantify potassium ions in undiluted human blood and plasma by measuring the distance or the rate of the color propagation. The sensor was composed of K+-selective nanospheres embedded in an agarose hydrogel where mass transport was diffusion controlled. The sensor's color-changing rate and the distance of color propagation depended linearly on the logarithm of K+ activity. A theoretical model was established and fully supported the experimental findings. This work lays the foundation of a new family of optical ion sensors for direct determination of common blood electrolytes.
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Affiliation(s)
- Xinfeng Du
- Department
of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Xiaojiang Xie
- Department
of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
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Wang X, Zhang Q, Nam C, Hickner M, Mahoney M, Meyerhoff ME. An Ionophore-Based Anion-Selective Optode Printed on Cellulose Paper. Angew Chem Int Ed Engl 2017; 56:11826-11830. [PMID: 28715617 DOI: 10.1002/anie.201706147] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Indexed: 11/09/2022]
Abstract
A general anion-sensing platform is reported based on a portable and cost-effective ion-selective optode and a smartphone detector equipped with a color analysis app. In contrast to traditional anion-selective optodes using a hydrophobic polymer and/or plasticizer to dissolve hydrophobic sensing elements, the new optode relies on hydrophilic cellulose paper. The anion ionophore and a lipophilic pH indicator are inkjet-printed and adsorbed on paper and form a "dry" hydrophobic sensing layer. Porous cellulose sheets also allow the sensing site to be modified with dried buffer that prevents any sample pH dependence of the observed color change. A highly selective fluoride optode using an AlIII -porphyrin ionophore is examined as an initial example of this new anion sensing platform for measurements of fluoride levels in drinking water samples. Apart from Lewis acid-base recognition, hydrogen bonding recognition is also compatible with this sensing platform.
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Affiliation(s)
- Xuewei Wang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Qi Zhang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Changwoo Nam
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Michael Hickner
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Mollie Mahoney
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mark E Meyerhoff
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
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21
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Wang X, Zhang Q, Nam C, Hickner M, Mahoney M, Meyerhoff ME. An Ionophore-Based Anion-Selective Optode Printed on Cellulose Paper. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706147] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Xuewei Wang
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109 USA
| | - Qi Zhang
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109 USA
| | - Changwoo Nam
- Department of Materials Science and Engineering; Pennsylvania State University; University Park PA 16802 USA
| | - Michael Hickner
- Department of Materials Science and Engineering; Pennsylvania State University; University Park PA 16802 USA
| | - Mollie Mahoney
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109 USA
| | - Mark E. Meyerhoff
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109 USA
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