{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T19:26:02Z","timestamp":1768591562541,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2023,2,15]],"date-time":"2023-02-15T00:00:00Z","timestamp":1676419200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"EITB Maratoia","award":["BIO21\/COV\/032\/BD"],"award-info":[{"award-number":["BIO21\/COV\/032\/BD"]}]},{"name":"EITB Maratoia","award":["BIO21\/COV\/032\/BD"],"award-info":[{"award-number":["BIO21\/COV\/032\/BD"]}]},{"name":"Iniciativa Medtech","award":["BIO21\/COV\/032\/BD"],"award-info":[{"award-number":["BIO21\/COV\/032\/BD"]}]},{"name":"Iniciativa Medtech","award":["BIO21\/COV\/032\/BD"],"award-info":[{"award-number":["BIO21\/COV\/032\/BD"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biosensors"],"abstract":"<jats:p>Even with the widespread uptake of vaccines, the SARS-CoV-2-induced COVID-19 pandemic continues to overwhelm many healthcare systems worldwide. Consequently, massive scale molecular diagnostic testing remains a key strategy to control the ongoing pandemic, and the need for instrument-free, economic and easy-to-use molecular diagnostic alternatives to PCR remains a goal of many healthcare providers, including WHO. We developed a test (Repvit) based on gold nanoparticles that can detect SARS-CoV-2 RNA directly from nasopharyngeal swab or saliva samples with a limit of detection (LOD) of 2.1 \u00d7 105 copies mL\u22121 by the naked eye (or 8 \u00d7 104 copies mL\u22121 by spectrophotometer) in less than 20 min, without the need for any instrumentation, and with a manufacturing price of &lt;$1. We tested this technology on 1143 clinical samples from RNA extracted from nasopharyngeal swabs (n = 188), directly from saliva samples (n = 635; assayed by spectrophotometer) and nasopharyngeal swabs (n = 320) from multiple centers and obtained sensitivity values of 92.86%, 93.75% and 94.57% and specificities of 93.22%, 97.96% and 94.76%, respectively. To our knowledge, this is the first description of a colloidal nanoparticle assay that allows for rapid nucleic acid detection at clinically relevant sensitivity without the need for external instrumentation that could be used in resource-limited settings or for self-testing.<\/jats:p>","DOI":"10.3390\/bios13020275","type":"journal-article","created":{"date-parts":[[2023,2,15]],"date-time":"2023-02-15T03:09:21Z","timestamp":1676430561000},"page":"275","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Validation of Rapid and Economic Colorimetric Nanoparticle Assay for SARS-CoV-2 RNA Detection in Saliva and Nasopharyngeal Swabs"],"prefix":"10.3390","volume":"13","author":[{"given":"Mar\u00eda","family":"Armesto","sequence":"first","affiliation":[{"name":"Molecular Oncology Group, Biodonostia Research Institute, 20014 San Sebasti\u00e1n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2786-8750","authenticated-orcid":false,"given":"Mathias","family":"Charconnet","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2787-7094","authenticated-orcid":false,"given":"Jos\u00e9 M.","family":"Marim\u00f3n","sequence":"additional","affiliation":[{"name":"Respiratory Infection and Antimicrobial Resistance Group, Biodonostia Research Institute, 20014 San Sebasti\u00e1n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6709-2550","authenticated-orcid":false,"given":"Cristina L\u00eda","family":"Fern\u00e1ndez Regueiro","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7967-4275","authenticated-orcid":false,"given":"Jia","family":"Jia","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"},{"name":"School of Life Sciences, Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tingdong","family":"Yan","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ane","family":"Sorarrain","sequence":"additional","affiliation":[{"name":"Respiratory Infection and Antimicrobial Resistance Group, Biodonostia Research Institute, 20014 San Sebasti\u00e1n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3458-8450","authenticated-orcid":false,"given":"Marek","family":"Grzelczak","sequence":"additional","affiliation":[{"name":"Colloidal Systems Chemistry, Centro de F\u00edsica de Materiales (CSIC-UPV\/EHU), 20018 San Sebasti\u00e1n, Spain"},{"name":"Donostia Institute of Physics Centre (DIPC), 20018 San Sebasti\u00e1n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mar\u00eda","family":"Sanrom\u00e1n","sequence":"additional","affiliation":[{"name":"Colloidal Systems Chemistry, Centro de F\u00edsica de Materiales (CSIC-UPV\/EHU), 20018 San Sebasti\u00e1n, Spain"},{"name":"Donostia Institute of Physics Centre (DIPC), 20018 San Sebasti\u00e1n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5041-1674","authenticated-orcid":false,"given":"M\u00f3nica","family":"Vicente","sequence":"additional","affiliation":[{"name":"Molecular Oncology Group, Biodonostia Research Institute, 20014 San Sebasti\u00e1n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6931-1224","authenticated-orcid":false,"given":"Boris","family":"Klempa","sequence":"additional","affiliation":[{"name":"Biomedical Research Center, Institute of Virology, Slovak Academy of Sciences, D\u00fabravsk\u00e1 Cesta 9, Bratislava 845 05, Slovakia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Javier","family":"Zubiria","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuan","family":"Peng","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lei","family":"Zhang","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jianhua","family":"Zhang","sequence":"additional","affiliation":[{"name":"Sino-Swiss Institute of Advanced Technology (SSIAT), Shanghai University, Shanghai 201907, China"},{"name":"School of Microelectronics, Shanghai University, Shanghai 201907, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8882-1131","authenticated-orcid":false,"given":"Charles 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