Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode
AlGaN/GaN heterostructure-based devices can be engineered through heterostructure design to have a high transconductance near zero gate–drain voltage, potentially enabling high sensitivity, reference electrode free, ion sensing. As a proof of concept, these devices were coated with a PVC-based membr...
| Main Authors: | , , , , , , |
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| Format: | Journal Article |
| Published: |
Elsevier SA
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/24180 |
| _version_ | 1848751357748576256 |
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| author | Myers, M Khir, F Podolska, Anna Umana-Membreno, G Nener, B Baker, M Parish, G |
| author_facet | Myers, M Khir, F Podolska, Anna Umana-Membreno, G Nener, B Baker, M Parish, G |
| author_sort | Myers, M |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | AlGaN/GaN heterostructure-based devices can be engineered through heterostructure design to have a high transconductance near zero gate–drain voltage, potentially enabling high sensitivity, reference electrode free, ion sensing. As a proof of concept, these devices were coated with a PVC-based membrane containing a plasticizer and an ionophore to detect nitrate ions in solution. The sensor response is measured as a change in conductivity across two contacts using a Kelvin probe (or four-contact) geometry, with the current between the two outer contacts kept constant. We show that this sensor for nitrate is sensitive and stable with a rapid response time (i.e. less than 60 s). The detection limit remains consistently low over multiple runs/days. In a 0.1 M KH2PO4 ion buffer, a detection limit of less than 1 × 10-6 M and a linear response range of 10-6–10-3 M were achieved. Furthermore, detection limits of approximately 10-6 M and 10-4 M in 0.1 M K2SO4 and 0.1 M KCl ion buffers, respectively, were demonstrated. In a 0.1 M KH2PO4 ion buffer, there was minimal change in sensor response upon addition of KOH increasing the pH from approximately 4–11. As a control, devices without a PVC membrane coating were tested under identical conditions and exhibited negligible response to nitrate ion exposure. Furthermore, using transistor theory, we show that the apparent gate response is near-Nenrstian under a variety of conditions. The success of this study paves the way for extending this technology to selectively sensing multiple ions in water through incorporation of the appropriate polymer based membranes on arrays of devices. |
| first_indexed | 2025-11-14T07:51:27Z |
| format | Journal Article |
| id | curtin-20.500.11937-24180 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:51:27Z |
| publishDate | 2013 |
| publisher | Elsevier SA |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-241802017-09-13T15:53:17Z Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode Myers, M Khir, F Podolska, Anna Umana-Membreno, G Nener, B Baker, M Parish, G AlGaN/GaN heterostructure-based devices can be engineered through heterostructure design to have a high transconductance near zero gate–drain voltage, potentially enabling high sensitivity, reference electrode free, ion sensing. As a proof of concept, these devices were coated with a PVC-based membrane containing a plasticizer and an ionophore to detect nitrate ions in solution. The sensor response is measured as a change in conductivity across two contacts using a Kelvin probe (or four-contact) geometry, with the current between the two outer contacts kept constant. We show that this sensor for nitrate is sensitive and stable with a rapid response time (i.e. less than 60 s). The detection limit remains consistently low over multiple runs/days. In a 0.1 M KH2PO4 ion buffer, a detection limit of less than 1 × 10-6 M and a linear response range of 10-6–10-3 M were achieved. Furthermore, detection limits of approximately 10-6 M and 10-4 M in 0.1 M K2SO4 and 0.1 M KCl ion buffers, respectively, were demonstrated. In a 0.1 M KH2PO4 ion buffer, there was minimal change in sensor response upon addition of KOH increasing the pH from approximately 4–11. As a control, devices without a PVC membrane coating were tested under identical conditions and exhibited negligible response to nitrate ion exposure. Furthermore, using transistor theory, we show that the apparent gate response is near-Nenrstian under a variety of conditions. The success of this study paves the way for extending this technology to selectively sensing multiple ions in water through incorporation of the appropriate polymer based membranes on arrays of devices. 2013 Journal Article http://hdl.handle.net/20.500.11937/24180 10.1016/j.snb.2013.02.006 Elsevier SA restricted |
| spellingShingle | Myers, M Khir, F Podolska, Anna Umana-Membreno, G Nener, B Baker, M Parish, G Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode |
| title | Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode |
| title_full | Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode |
| title_fullStr | Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode |
| title_full_unstemmed | Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode |
| title_short | Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode |
| title_sort | nitrate ion detection using algan/gan heterostructure-based devices without a reference electrode |
| url | http://hdl.handle.net/20.500.11937/24180 |