{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,22]],"date-time":"2025-10-22T23:13:38Z","timestamp":1761174818827,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2022,7,29]],"date-time":"2022-07-29T00:00:00Z","timestamp":1659052800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)","award":["159897\/2019-0","402195\/2020-5"],"award-info":[{"award-number":["159897\/2019-0","402195\/2020-5"]}]},{"name":"Sistema Nacional de Laborat\u00f3rios em Nanotecnologias (SisNANO)","award":["159897\/2019-0","402195\/2020-5"],"award-info":[{"award-number":["159897\/2019-0","402195\/2020-5"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior\u2013Brasil (CAPES)","award":["159897\/2019-0","402195\/2020-5"],"award-info":[{"award-number":["159897\/2019-0","402195\/2020-5"]}]},{"name":"CNPq","award":["159897\/2019-0","402195\/2020-5"],"award-info":[{"award-number":["159897\/2019-0","402195\/2020-5"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The coronavirus pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has accelerated the development of biosensors based on new materials and techniques. Here, we present our effort to develop a fast and affordable optical biosensor using photoluminescence spectroscopy for anti-SARS-CoV-2 antibody detection. The biosensor was fabricated with a thin layer of the semiconductor polymer Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-2,2\u2032-bithiophene-5,5\u2032-diyl)] (F8T2) as a signal transducer material. We mounted the biosensors by depositing a layer of F8T2 and an engineered version of RBD from the SARS-CoV-2 spike protein with a tag to promote hydrophobic interaction between the protein and the polymeric surface. We validated the biosensor sensitivity with decreasing anti-RBD polyclonal IgG concentrations and challenged the biosensor specificity with human serum samples from both COVID-19 negative and positive individuals. The antibody binding to the immobilized antigen shifted the F8T2 photoluminescence spectrum even at the low concentration of 0.0125 \u00b5g\/mL. A volume as small as one drop of serum (100 \u00b5L) was sufficient to distinguish a positive from a negative sample without requiring multiple washing steps and secondary antibody reactions.<\/jats:p>","DOI":"10.3390\/s22155673","type":"journal-article","created":{"date-parts":[[2022,7,29]],"date-time":"2022-07-29T01:41:16Z","timestamp":1659058876000},"page":"5673","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Optical Biosensor for the Detection of Infectious Diseases Using the Copolymer F8T2 with Application to COVID-19"],"prefix":"10.3390","volume":"22","author":[{"given":"Maiara de Jesus","family":"Bassi","sequence":"first","affiliation":[{"name":"Physics Department, Federal University of Paran\u00e1, Curitiba 81531-980, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maritza","family":"Araujo Todo Bom","sequence":"additional","affiliation":[{"name":"Biochemistry Department, Federal University of Paran\u00e1, Curitiba 81531-980, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maria Luisa","family":"Terribile Budel","sequence":"additional","affiliation":[{"name":"Biochemistry Department, Federal University of Paran\u00e1, Curitiba 81531-980, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Emanuel","family":"Maltempi de Souza","sequence":"additional","affiliation":[{"name":"Biochemistry Department, Federal University of Paran\u00e1, Curitiba 81531-980, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marcelo","family":"M\u00fcller dos Santos","sequence":"additional","affiliation":[{"name":"Biochemistry Department, Federal University of Paran\u00e1, Curitiba 81531-980, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lucimara Stolz","family":"Roman","sequence":"additional","affiliation":[{"name":"Physics Department, Federal University of Paran\u00e1, Curitiba 81531-980, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Awassa, L., Jdey, I., Dhahri, H., Hcini, G., Mahmood, A., Othman, E., and Haneef, M. (2022). Study of Different Deep Learning Methods for Coronavirus (COVID-19) Pandemic: Taxonomy, Survey and Insights. Sensors, 22.","DOI":"10.3390\/s22051890"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1270","DOI":"10.1021\/acssensors.0c02561","article-title":"Microfluidic Magneto Immunosensor for Rapid, High Sensitivity Measurements of SARS-CoV-2 Nucleocapsid Protein in Serum","volume":"6","author":"Li","year":"2021","journal-title":"ACS Sens."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Abayomi-Alli, O.O., Dama\u0161evi\u010dius, R., Maskeli\u016bnas, R., and Misra, S. (2022). An Ensemble Learning Model for COVID-19 Detection from Blood Test Samples. Sensors, 22.","DOI":"10.3390\/s22062224"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e2005448","DOI":"10.1002\/adma.202005448","article-title":"A Review of Piezoelectric and Magnetostrictive Biosensor Materials for Detection of COVID-19 and Other Viruses","volume":"33","author":"Narita","year":"2021","journal-title":"Adv. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Bla\u0161kovi\u010dov\u00e1, J., and Labuda, J. (2022). Effect of Triclosan and Silver Nanoparticles on DNA Damage Investigated with DNA-Based Biosensor. Sensors, 22.","DOI":"10.3390\/s22124332"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Bandeliuk, O., Assaf, A., Bittel, M., Durand, M.-J., and Thouand, G. (2022). Development and Automation of a Bacterial Biosensor to the Targeting of the Pollutants Toxic Effects by Portable Raman Spectrometer. Sensors, 22.","DOI":"10.3390\/s22124352"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"112578","DOI":"10.1016\/j.bios.2020.112578","article-title":"Detection of antibodies against SARS-CoV-2 spike protein by gold nanospikes in an opto-microfluidic chip","volume":"169","author":"Funari","year":"2020","journal-title":"Biosens. Bioelectron."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1690","DOI":"10.1021\/acssensors.8b00422","article-title":"Ultrasensitive Label- and PCR-Free Genome Detection Based on Cooperative Hybridization of Silicon Nanowires Optical Biosensors","volume":"3","author":"Leonardi","year":"2018","journal-title":"ACS Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1800561","DOI":"10.1002\/macp.201800561","article-title":"Progress in the Development of Intrinsically Conducting Polymer Composites as Biosensors","volume":"220","author":"Prajapati","year":"2019","journal-title":"Macromol. Chem. Phys."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"103702","DOI":"10.1063\/1.5108891","article-title":"Magnetically aggregated biosensors for sensitive detection of biomarkers at low concentrations","volume":"115","author":"Burg","year":"2019","journal-title":"Appl. Phys. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Steglich, P., Lecci, G., and Mai, A. (2022). Surface Plasmon Resonance (SPR) Spectroscopy and Photonic Integrated Circuit (PIC) Biosensors: A Comparative Review. Sensors, 22.","DOI":"10.3390\/s22082901"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"114202","DOI":"10.1016\/j.bios.2022.114202","article-title":"Retroreflection-based optical biosensing: From concept to applications","volume":"207","author":"Han","year":"2022","journal-title":"Biosens. Bioelectron."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"187","DOI":"10.3390\/surfaces5010012","article-title":"Electrochemical Biosensor Based on Laser-Induced Graphene for COVID-19 Diagnosing: Rapid and Low-Cost Detection of SARS-CoV-2 Biomarker Antibodies","volume":"5","author":"Oliveira","year":"2022","journal-title":"Surfaces"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.1021\/acssensors.9b00230","article-title":"Flexible Biosensors for the Impedimetric Detection of Protein Targets Using Silk-Conductive Polymer Biocomposites","volume":"4","author":"Xu","year":"2019","journal-title":"ACS Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/j.orgel.2018.11.001","article-title":"A multipurpose conjugated polymer: Electrochromic device and biosensor construction for glucose detection","volume":"65","author":"Soylemez","year":"2019","journal-title":"Org. Electron."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.aca.2018.01.027","article-title":"Conjugated polymer nanoparticles-based fluorescent biosensor for ultrasensitive detection of hydroquinone","volume":"1012","author":"Liu","year":"2018","journal-title":"Anal. Chim. Acta"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7778","DOI":"10.1088\/0022-3727\/40\/24\/027","article-title":"Electrosprayed superhydrophobic PTFE: A non-contaminating surface","volume":"40","author":"Burkarter","year":"2007","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1853","DOI":"10.1016\/j.msec.2013.01.035","article-title":"A review study of (bio)sensor systems based on conducting polymers","volume":"33","author":"Ates","year":"2013","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1806712","DOI":"10.1002\/adma.201806712","article-title":"Conjugated Polymers for Assessing and Controlling Biological Functions","volume":"31","author":"Zeglio","year":"2019","journal-title":"Adv. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6618","DOI":"10.1021\/acsami.7b18275","article-title":"Conjugated Polymer-Based Photoelectrochemical Cytosensor with Turn-On Enable Signal for Sensitive Cell Detection","volume":"10","author":"Liu","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"114392","DOI":"10.1016\/j.jpba.2021.114392","article-title":"Nanostructured sensor platform based on organic polymer conjugated to metallic nanoparticle for the impedimetric detection of SARS-CoV-2 at various stages of viral infection","volume":"206","author":"Avelino","year":"2021","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2287","DOI":"10.1016\/j.solmat.2011.03.043","article-title":"The role of the double peaked absorption spectrum in the efficiency of solar cells based on donor-acceptor-donor copolymers","volume":"95","author":"Canestraro","year":"2011","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"513457","DOI":"10.1155\/2012\/513457","article-title":"Thickness effect on F8T2\/C 60 bilayer photovoltaic devices","volume":"2012","author":"Yamamoto","year":"2012","journal-title":"J. Nanotechnol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"11244","DOI":"10.1039\/C5CP01285F","article-title":"The effect of thermal annealing on the charge transfer dynamics of a donor-acceptor copolymer and fullerene: F8T2 and F8T2: PCBM","volume":"17","author":"Yamamoto","year":"2015","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"16035","DOI":"10.1021\/acs.jpcc.7b05427","article-title":"Conformational Change on a Bithiophene-Based Copolymer Induced by Additive Treatment: Application in Organic Photovoltaics","volume":"121","author":"Lourenco","year":"2017","journal-title":"J. Phys. Chem. C"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"27946","DOI":"10.1021\/acs.jpcc.0c09459","article-title":"Energy transfer in aqueously dispersed organic semiconductor nanoparticles","volume":"124","author":"Roozbeh","year":"2020","journal-title":"J. Phys. Chem. C"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"116740","DOI":"10.1016\/j.synthmet.2021.116740","article-title":"Non-radiative energy transfer in aqueously dispersed polymeric nanoparticles for photovoltaic applications","volume":"275","author":"Wouk","year":"2021","journal-title":"Synth. Met."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1038\/s41586-020-2180-5","article-title":"Structure of the SARS-CoV-2 spike receptor-binding domain bound to the ACE2 receptor","volume":"581","author":"Lan","year":"2020","journal-title":"Nature"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1007\/s41403-020-00122-w","article-title":"P-FAB: A Fiber-Optic Biosensor Device for Rapid Detection of COVID-19","volume":"5","author":"Murugan","year":"2020","journal-title":"Trans. Indian Natl. Acad. Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2616","DOI":"10.1007\/s11434-013-5716-3","article-title":"Effect of protein molecules on the photoluminescence properties and stability of water-soluble CdSe\/ZnS core-shell quantum dots","volume":"58","author":"Zhang","year":"2013","journal-title":"Chin. Sci. Bull."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Vizzini, P., Braidot, M., Vidic, J., and Manzano, M. (2019). Electrochemical and optical biosensors for the detection of Campylobacter and Listeria: An update look. Micromachines, 10.","DOI":"10.3390\/mi10080500"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"9817","DOI":"10.1016\/j.apsusc.2011.06.028","article-title":"Van Conducting polymer film-based immunosensors using carbon nanotube\/antibodies doped polypyrrole","volume":"257","author":"Tam","year":"2011","journal-title":"Appl. Surf. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1163\/156855506775526205","article-title":"Conducting polymers: An emerging field of biosensors","volume":"9","author":"Borole","year":"2006","journal-title":"Des. Monomers Polym."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1007\/s00604-003-0066-5","article-title":"Application of Conducting Polymers in Chemical Analysis","volume":"143","author":"Trojanowicz","year":"2003","journal-title":"Microchim. Acta"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.msec.2014.12.020","article-title":"Simple method for preparing glucose biosensor based on in-situ polypyrrole cross-linked chitosan\/glucose oxidase\/gold bionanocomposite film","volume":"48","year":"2015","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_36","first-page":"111","article-title":"Nature of the antigen-antibody interaction. Primary and secondary bonds: Optimal conditions for association and dissociation","volume":"376","author":"Good","year":"1986","journal-title":"J. Chromatogr. B Biomed. Sci. Appl."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Psychogios, N., Hau, D.D., Peng, J., Guo, A.C., Mandal, R., Bouatra, S., Sinelnikov, I., Krishnamurthy, R., Eisner, R., and Gautam, B. (2011). The human serum metabolome. PLoS ONE, 6.","DOI":"10.1371\/journal.pone.0016957"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/15\/5673\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:58:48Z","timestamp":1760140728000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/15\/5673"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,29]]},"references-count":37,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["s22155673"],"URL":"https:\/\/doi.org\/10.3390\/s22155673","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2022,7,29]]}}}