Publicação
Point-of-care testing of nitrite in oral medicine : application and validation of an enzymatic biosensor in human saliva
| datacite.subject.fos | Ciências Médicas::Biotecnologia Médica | |
| datacite.subject.sdg | 03:Saúde de Qualidade | |
| dc.contributor.author | Gaspar, Sara Rodrigues | |
| dc.contributor.author | Proença, Luís | |
| dc.contributor.author | Alves, Ricardo | |
| dc.contributor.author | Almeida, Maria Gabriela | |
| dc.date.accessioned | 2026-05-19T15:25:20Z | |
| dc.date.available | 2026-05-19T15:25:20Z | |
| dc.date.issued | 2025-08 | |
| dc.description.abstract | Periodontal disease (PD) is a chronic inflammatory condition triggered by bacterial biofilms and progresses through two main stages: gingivitis and periodontitis. The existing diagnostic methods remain time-consuming and require clinical expertise. Salivary nitrite, a stable end-product of nitric oxide produced during inflammation, has emerged as a promising biomarker for PD. However, its reliable quantification in saliva typically relies on laboratory-based assays that are unsuited to clinical workflows. This study aimed to test and validate a new nitrite point-of-care test (POCT) for oral medicine. Building on previous research, we developed a biosensing platform based on screen-printed carbon electrodes modified with a selective enzyme, the cytochrome c nitrite reductase. To adapt bioelectrodes for salivary analysis, they were further modified with a poly(vinyl) alcohol coating and a biochemical oxygen scavenger system (ascorbate oxidase and ascorbate). The nitrite biosensor achieved a suitable linear range of 5–300 μM, with a sensitivity of 0.015 μM−1, validated against the gold-standard Griess method. Unlike the Griess reaction, the biosensor was unaffected by sample turbidity, rendering centrifugation unnecessary. Additionally, we observed that sample freezing altered nitrite concentrations, increasing levels in non-centrifuged samples, while decreasing them in previously clarified samples. These findings highlight the need for real-time analysis and call into question the reliability of previously published data that overlooked these variables. Therefore, our results demonstrate the potential of the nitrite biosensor as a novel salivary POCT and emphasize the critical need for standardized sample-handling protocols. | eng |
| dc.identifier.citation | Gaspar, S. R., Proença, L., Alves, R., & Almeida, M. G. (2025). Point-of-care testing of nitrite in oral medicine - Application and validation of an enzymatic biosensor in human saliva. Sensing and Bio-Sensing Research, 49, Artigo 100860. https://doi.org/10.1016/j.sbsr.2025.100860 | |
| dc.identifier.doi | 10.1016/j.sbsr.2025.100860 | |
| dc.identifier.issn | 2214-1804 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/63200 | |
| dc.language.iso | eng | |
| dc.peerreviewed | yes | |
| dc.publisher | Elsevier | |
| dc.relation.hasversion | https://doi.org/10.1016/j.sbsr.2025.100860 | |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject | periodontal disease | |
| dc.subject | saliva | |
| dc.subject | nitrite | |
| dc.subject | biosensors | |
| dc.subject | point-of-care test | |
| dc.title | Point-of-care testing of nitrite in oral medicine : application and validation of an enzymatic biosensor in human saliva | eng |
| dc.type | contribution to journal | |
| dspace.entity.type | Publication | |
| oaire.citation.startPage | 100860 | |
| oaire.citation.title | Sensing and Bio-Sensing Research | |
| oaire.citation.volume | 49 | |
| oaire.version | http://purl.org/coar/version/c_970fb48d4fbd8a85 |