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Sedhu N, Jagadeesh Kumar J, Sivaguru P, Raj V. Electrochemical detection of riboflavin in pharmaceutical and food samples using in situ electropolymerized glycine coated pencil graphite electrode. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.117037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Serbest Z, Gorduk O, Sahin Y. One-Step Electrochemical Fabrication of Lithium-Intercalated Pencil Graphite Electrode (PGE) for the Differential Pulse Voltammetric (DPV) Determination of l-Tyrosine. ANAL LETT 2022. [DOI: 10.1080/00032719.2022.2117370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Zeynep Serbest
- Faculty of Arts and Science, Department of Chemistry, Yildiz Technical University, Istanbul, Turkey
| | - Ozge Gorduk
- Faculty of Arts and Science, Department of Chemistry, Yildiz Technical University, Istanbul, Turkey
| | - Yucel Sahin
- Faculty of Arts and Science, Department of Chemistry, Yildiz Technical University, Istanbul, Turkey
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Chip-Based Spectrofluorimetric Determination of Iodine in a Multi-Syringe Flow Platform with and without In-Line Digestion-Application to Salt, Pharmaceuticals, and Algae Samples. Molecules 2022; 27:molecules27041325. [PMID: 35209114 PMCID: PMC8877039 DOI: 10.3390/molecules27041325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/13/2022] [Accepted: 02/14/2022] [Indexed: 02/05/2023] Open
Abstract
In this work, a flow-based spectrofluorimetric method for iodine determination was developed. The system consisted of a miniaturized chip-based flow manifold for solutions handling and with integrated spectrofluorimetric detection. A multi-syringe module was used as a liquid driver. Iodide was quantified from its catalytic effect on the redox reaction between Ce(IV) and As(III), based on the Sandell–Kolthoff reaction. The method was applied for the determination of iodine in salt, pharmaceuticals, supplement pills, and seaweed samples without off-line pre-treatment. An in-line oxidation process, aided by UV radiation, was implemented to analyse some samples (supplement pills and seaweed samples) to eliminate interferences and release iodine from organo-iodine compounds. This feature, combined with the fluorometric reaction, makes this method simpler, faster, and more sensitive than the classic approach of the Sandell–Kolthoff reaction. The method allowed iodine to be determined within a range of 0.20–4.0 µmol L−1, with or without the in-line UV digestion, with a limit of detection of 0.028 µmol L−1 and 0.025 µmol L−1, respectively.
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Leeb E, Wielend D, Schimanofsky C, Sariciftci NS. Substrate and pH‐dependent homogeneous electrocatalysis using riboflavin for oxygen reduction. ELECTROCHEMICAL SCIENCE ADVANCES 2022. [DOI: 10.1002/elsa.202100211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Elisabeth Leeb
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
| | - Dominik Wielend
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
| | - Corina Schimanofsky
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
| | - Niyazi Serdar Sariciftci
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
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Galiga HF, Sevilla FB. Smartphone-based optical transduction for the rapid microscale assessment of iodate in table salt. Talanta 2021; 232:122450. [PMID: 34074434 DOI: 10.1016/j.talanta.2021.122450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/18/2021] [Accepted: 04/19/2021] [Indexed: 11/18/2022]
Abstract
The measurement of iodine in table salt is vital for the successful implementation of the universal salt iodization (USI) program to fight iodine deficiency disorders (IDDs). This paper presents a smartphone-based optical transduction system for iodine measurement in table salt. The method was based on the response in the blue color space generated by the complex formed between the starch/iodide reagent and iodate in the salt sample. The parameters for the color reaction and for the image capture affected the response and were optimized. A matrix effect caused by NaCl was observed and was eliminated through matrix matching by incorporating NaCl in the standard solutions. The optimized method yielded a highly linear response to iodate concentrations ranging from 10 to 160 mg kg-1 (r = 0.9993) with a limit of detection of 2.8 mg kg-1. The method exhibited good accuracy and precision, based on AOAC standards. It produced results that were in agreement with those obtained using the reference method at the 95% confidence level. The smartphone performs optical transduction, as well as signal processing, to yield a display of the iodate concentration in the salt sample. The use of smartphones presents a simple, inexpensive, portable, and widely available device for on-site analysis of iodate in table salt.
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Affiliation(s)
- Henley F Galiga
- The Graduate School, University of Santo Tomas, Manila, 1015, Philippines.
| | - Fortunato B Sevilla
- The Graduate School, University of Santo Tomas, Manila, 1015, Philippines; Research Center for the Natural and Applied Sciences, University of Santo Tomas, Manila, 1015, Philippines.
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Nellaiappan S, Kumar AS. Reductive cleavage of methyl orange under formation of a redox-active hydroquinone/polyaniline nanocomposite on an electrode modified with MWCNTs, and its application to flow injection analysis of ascorbic acid at low potential and neutral pH value. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2339-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Radzevič A, Niaura G, Ignatjev I, Rakickas T, Celiešiūtė R, Pauliukaite R. Electropolymerisation of the natural monomer riboflavin and its characterisation. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.11.166] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kormányos A, Hossain MS, Ghadimkhani G, Johnson JJ, Janáky C, de Tacconi NR, Foss FW, Paz Y, Rajeshwar K. Flavin Derivatives with Tailored Redox Properties: Synthesis, Characterization, and Electrochemical Behavior. Chemistry 2016; 22:9209-17. [PMID: 27243969 DOI: 10.1002/chem.201600207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Indexed: 11/11/2022]
Abstract
This study establishes structure-property relationships for four synthetic flavin molecules as bioinspired redox mediators in electro- and photocatalysis applications. The studied flavin compounds were disubstituted with polar substituents at the N1 and N3 positions (alloxazine) or at the N3 and N10 positions (isoalloxazines). The electrochemical behavior of one such synthetic flavin analogue was examined in detail in aqueous solutions of varying pH in the range from 1 to 10. Cyclic voltammetry, used in conjunction with hydrodynamic (rotating disk electrode) voltammetry, showed quasi-reversible behavior consistent with freely diffusing molecules and an overall global 2e(-) , 2H(+) proton-coupled electron transfer scheme. UV/Vis spectroelectrochemical data was also employed to study the pH-dependent electrochemical behavior of this derivative. Substituent effects on the redox behavior were compared and contrasted for all the four compounds, and visualized within a scatter plot framework to afford comparison with prior knowledge on mostly natural flavins in aqueous media. Finally, a preliminary assessment of one of the synthetic flavins was performed of its electrocatalytic activity toward dioxygen reduction as a prelude to further (quantitative) studies of both freely diffusing and tethered molecules on various electrode surfaces.
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Affiliation(s)
- Attila Kormányos
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA.,Department of Physical Chemistry and Materials Science, University of Szeged, Szeged, 6720, Hungary.,MTA-SZTE "Lendület" Photoelectrochemistry Research Group, Rerrich Square 1, Szeged, 6720, Hungary
| | - Mohammad S Hossain
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA
| | - Ghazaleh Ghadimkhani
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA
| | - Joe J Johnson
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA
| | - Csaba Janáky
- Department of Physical Chemistry and Materials Science, University of Szeged, Szeged, 6720, Hungary.,MTA-SZTE "Lendület" Photoelectrochemistry Research Group, Rerrich Square 1, Szeged, 6720, Hungary
| | - Norma R de Tacconi
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA
| | - Frank W Foss
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA
| | - Yaron Paz
- Department of Chemical Engineering, Technion, Haifa, 32000, Israel
| | - Krishnan Rajeshwar
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Texas, 76019, USA.
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Mallakpour S, Soltanian S. Surface functionalization of carbon nanotubes: fabrication and applications. RSC Adv 2016. [DOI: 10.1039/c6ra24522f] [Citation(s) in RCA: 190] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
This review highlights recent development in functionalization of CNTs and their applications.
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Affiliation(s)
- Shadpour Mallakpour
- Organic Polymer Chemistry Research Laboratory
- Department of Chemistry
- Isfahan University of Technology
- Isfahan
- Islamic Republic of Iran
| | - Samaneh Soltanian
- Organic Polymer Chemistry Research Laboratory
- Department of Chemistry
- Isfahan University of Technology
- Isfahan
- Islamic Republic of Iran
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The electrochemical copolymerization of diphenylamine and p-phenylenediamine and its use as a modified electrode for amperometric determination of iodate. J Electroanal Chem (Lausanne) 2014. [DOI: 10.1016/j.jelechem.2014.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Thangaraj R, Nellaiappan S, Sudhakaran R, Kumar AS. A flow injection analysis coupled dual electrochemical detector for selective and simultaneous detection of guanine and adenine. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.01.066] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Gayathri P, Kumar AS. An Iron Impurity in Multiwalled Carbon Nanotube Complexes with Chitosan that Biomimics the Heme-Peroxidase Function. Chemistry 2013; 19:17103-12. [DOI: 10.1002/chem.201303075] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Indexed: 11/08/2022]
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