Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode
A graphene sample (EGr) was prepared by electrochemical exfoliation of graphite rods in solution containing 0.05 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> + 0.1 M H<sub>3</sub>BO<sub>3</sub> + 0.05 M NaCl. The exfoliation was performed b...
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| Format: | Article |
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MDPI AG
2021-01-01
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| Series: | Biosensors |
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| Online Access: | https://www.mdpi.com/2079-6374/11/2/36 |
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| author | Florina Pogacean Codruta Varodi Maria Coros Irina Kacso Teodora Radu Bogdan Ionut Cozar Valentin Mirel Stela Pruneanu |
| author_facet | Florina Pogacean Codruta Varodi Maria Coros Irina Kacso Teodora Radu Bogdan Ionut Cozar Valentin Mirel Stela Pruneanu |
| author_sort | Florina Pogacean |
| collection | DOAJ |
| description | A graphene sample (EGr) was prepared by electrochemical exfoliation of graphite rods in solution containing 0.05 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> + 0.1 M H<sub>3</sub>BO<sub>3</sub> + 0.05 M NaCl. The exfoliation was performed by applying a constant voltage (12 V) between the graphite rods, while the temperature was kept constant (18 °C) with a temperature-controlled cryostat. The structural investigation of the graphene sample, performed by X-ray powder diffraction (XRD), revealed that the sample consists of a mixture of few-layer (69%), multi-layer graphene (14%) and graphene oxide (17%). In addition, XPS analysis proved that the sample was triple-doped with heteroatoms such as nitrogen (1.7 at%), sulfur (2.5 at%), and boron (3 at%). The sample was deposited onto the surface of a clean, glassy carbon electrode (GC) and investigated for the non-enzymatic electrochemical detection of L-tryptophan (TRP). The electrocatalytic properties of the EGr/GC electrode led to a considerable decrease in the oxidation potential from +0.9 V (bare GC) to +0.72 V. In addition, the EGr/GC electrode has higher sensitivity (two times) and a lower detection limit (ten times) in comparison with the bare GC electrode. |
| first_indexed | 2024-03-09T03:21:08Z |
| format | Article |
| id | doaj.art-1665bfd50cbd4e889cfd5fb1e883cf15 |
| institution | Directory Open Access Journal |
| issn | 2079-6374 |
| language | English |
| last_indexed | 2024-03-09T03:21:08Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biosensors |
| spelling | doaj.art-1665bfd50cbd4e889cfd5fb1e883cf152023-12-03T15:07:59ZengMDPI AGBiosensors2079-63742021-01-011123610.3390/bios11020036Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified ElectrodeFlorina Pogacean0Codruta Varodi1Maria Coros2Irina Kacso3Teodora Radu4Bogdan Ionut Cozar5Valentin Mirel6Stela Pruneanu7National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaNational Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, RomaniaA graphene sample (EGr) was prepared by electrochemical exfoliation of graphite rods in solution containing 0.05 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> + 0.1 M H<sub>3</sub>BO<sub>3</sub> + 0.05 M NaCl. The exfoliation was performed by applying a constant voltage (12 V) between the graphite rods, while the temperature was kept constant (18 °C) with a temperature-controlled cryostat. The structural investigation of the graphene sample, performed by X-ray powder diffraction (XRD), revealed that the sample consists of a mixture of few-layer (69%), multi-layer graphene (14%) and graphene oxide (17%). In addition, XPS analysis proved that the sample was triple-doped with heteroatoms such as nitrogen (1.7 at%), sulfur (2.5 at%), and boron (3 at%). The sample was deposited onto the surface of a clean, glassy carbon electrode (GC) and investigated for the non-enzymatic electrochemical detection of L-tryptophan (TRP). The electrocatalytic properties of the EGr/GC electrode led to a considerable decrease in the oxidation potential from +0.9 V (bare GC) to +0.72 V. In addition, the EGr/GC electrode has higher sensitivity (two times) and a lower detection limit (ten times) in comparison with the bare GC electrode.https://www.mdpi.com/2079-6374/11/2/36electrochemical exfoliationdoped grapheneheteroatomsenhanced detection |
| spellingShingle | Florina Pogacean Codruta Varodi Maria Coros Irina Kacso Teodora Radu Bogdan Ionut Cozar Valentin Mirel Stela Pruneanu Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode Biosensors electrochemical exfoliation doped graphene heteroatoms enhanced detection |
| title | Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode |
| title_full | Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode |
| title_fullStr | Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode |
| title_full_unstemmed | Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode |
| title_short | Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode |
| title_sort | investigation of l tryptophan electrochemical oxidation with a graphene modified electrode |
| topic | electrochemical exfoliation doped graphene heteroatoms enhanced detection |
| url | https://www.mdpi.com/2079-6374/11/2/36 |
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