{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T15:37:37Z","timestamp":1781710657968,"version":"3.54.5"},"reference-count":22,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,6,23]],"date-time":"2025-06-23T00:00:00Z","timestamp":1750636800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Bulgarian National Science Fund","award":["K\u041f-06-H789\/14.12.2023"],"award-info":[{"award-number":["K\u041f-06-H789\/14.12.2023"]}]},{"name":"Bulgarian National Science Fund","award":["DO1-352\/13.12.2023"],"award-info":[{"award-number":["DO1-352\/13.12.2023"]}]},{"DOI":"10.13039\/501100005992","name":"Bulgarian Ministry of Education and Science (MES)","doi-asserted-by":"publisher","award":["K\u041f-06-H789\/14.12.2023"],"award-info":[{"award-number":["K\u041f-06-H789\/14.12.2023"]}],"id":[{"id":"10.13039\/501100005992","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005992","name":"Bulgarian Ministry of Education and Science (MES)","doi-asserted-by":"publisher","award":["DO1-352\/13.12.2023"],"award-info":[{"award-number":["DO1-352\/13.12.2023"]}],"id":[{"id":"10.13039\/501100005992","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>SPR has been recently established as a powerful tool for studying various cellular processes in real time and without the use of labeling agents. So far, all studies in this area have been performed using the Kretschmann method for SPR excitation. In our studies, we used grating-based SPR. Here, we investigated the feasibility of this approach in a cell-based assay applied for antiviral drug screening. It was found that the continuous-flow SPR detection used in the conventional SPR can be replaced by sequential signal measurements of SPR slides removed from the medium at fixed hours after seeding. A protocol ensuring correct measurements was established. SPR detection was performed up to 48 h after seeding the VERO E6 cell line in three experiments, in which the cells were (i) compound-untreated, (ii) compound-treated, and (iii) infected with human coronavirus type 229E and compound-treated. Therefore, the temporal variation in the SPR signal was determined, induced by the cell coverage on the slide, the compound toxicity, and its antiviral action. MTT analysis and microscopic observations were used as reference methods. The remarkable agreement found in the results of SPR detection proved the effectiveness and reliability of grating-based SPR applied in cell-based assays.<\/jats:p>","DOI":"10.3390\/s25133905","type":"journal-article","created":{"date-parts":[[2025,6,23]],"date-time":"2025-06-23T09:08:44Z","timestamp":1750669724000},"page":"3905","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Does a SPR-Based Cell-Based Assay Provide Reliable Results on the Toxicity and Efficacy of Antiviral Drugs?"],"prefix":"10.3390","volume":"25","author":[{"given":"Petia","family":"Genova-Kalou","sequence":"first","affiliation":[{"name":"National Center of Infectious and Parasitic Diseases, 44A \u201cGen. Stoletov\u201d Blvd., 1233 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3014-8535","authenticated-orcid":false,"given":"Evdokiya","family":"Hikova","sequence":"additional","affiliation":[{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d (IOMT), Bulgarian Academy of Sciences (BAS), 109 \u201cAcad. G. Bonchev\u201d Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Todor","family":"Kereziev","sequence":"additional","affiliation":[{"name":"Central Laboratory of Applied Physics, Bulgarian Academy of Sciences, 61 Sankt Petersburg Blvd., 4000 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Petar","family":"Kolev","sequence":"additional","affiliation":[{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d (IOMT), Bulgarian Academy of Sciences (BAS), 109 \u201cAcad. G. Bonchev\u201d Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vihar","family":"Mankov","sequence":"additional","affiliation":[{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d (IOMT), Bulgarian Academy of Sciences (BAS), 109 \u201cAcad. G. Bonchev\u201d Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Petar","family":"Veselinov","sequence":"additional","affiliation":[{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d (IOMT), Bulgarian Academy of Sciences (BAS), 109 \u201cAcad. G. Bonchev\u201d Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Trifon","family":"Valkov","sequence":"additional","affiliation":[{"name":"Prof. Ivan Kirov Hospital, Department of Infectious Diseases, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0927-0659","authenticated-orcid":false,"given":"Georgi","family":"Dyankov","sequence":"additional","affiliation":[{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d (IOMT), Bulgarian Academy of Sciences (BAS), 109 \u201cAcad. G. Bonchev\u201d Str., 1113 Sofia, Bulgaria"},{"name":"Central Laboratory of Applied Physics, Bulgarian Academy of Sciences, 61 Sankt Petersburg Blvd., 4000 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.snb.2016.01.118","article-title":"SPR biosensors: Historical perspectives and current challenges","volume":"229","author":"Singh","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"117079","DOI":"10.1016\/j.trac.2023.117079","article-title":"Surface plasmon resonance technology: Recent advances, applications and experimental cases","volume":"163","author":"Capelli","year":"2023","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Kumari, A., Yadav, A., Singh, O.P., and Sharan, P. (2024). 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