{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T05:53:10Z","timestamp":1791870790391,"version":"4.3.4"},"reference-count":29,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,3]],"date-time":"2025-10-03T00:00:00Z","timestamp":1759449600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004479","name":"Natural Science Foundation of Jiangxi Province","doi-asserted-by":"publisher","award":["20224BAB216058"],"award-info":[{"award-number":["20224BAB216058"]}],"id":[{"id":"10.13039\/501100004479","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100022957","name":"Double-Thousand Plan of Jiangxi Province","doi-asserted-by":"crossref","award":["jxsq2023101081"],"award-info":[{"award-number":["jxsq2023101081"]}],"id":[{"id":"10.13039\/100022957","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["32260623"],"award-info":[{"award-number":["32260623"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.mdpi.com"],"crossmark-restriction":true},"short-container-title":["Biosensors"],"abstract":"<jats:p>Staphylococcus aureus is a major pathogen responsible for staphylococcal food poisoning (SFP), with its pathogenicity primarily dependent on staphylococcal enterotoxins (SEs). Among these, staphylococcal enterotoxin A (SEA) is a critical risk factor due to its high toxicity, high detection rate (accounting for 80% of SFP cases), strong thermal stability, and resistance to hydrolysis. Traditional SEA immunoassays, such as enzyme-linked immunosorbent assay (ELISA), are prone to false-positive results caused by nonspecific binding interference from S. aureus surface protein A (SpA). In recent years, nanobodies (single-domain heavy-chain antibodies) have emerged as an ideal alternative to address SpA interference owing to their small molecular weight (15 kDa), high affinity, robust stability, and lack of Fc regions. In this study, based on a previously developed highly specific monoclonal antibody against SEA (mAb-4C6), four anti-SEA nanobodies paired with mAb-4C6 were obtained through two-part (four-round) of biopanning from a naive nanobody phage display library. Among these, SEA-4-20 and SEA-4-31 were selected as optimal candidates and paired with mAb-4C6 to construct double-antibody sandwich ELISAs. The detection limits for SEA were 0.135 ng\/mL and 0.137 ng\/mL, respectively, with effective elimination of SpA interference. This approach provides a reliable tool for rapid and accurate detection of SEA in food, clinical, and environmental samples.<\/jats:p>","DOI":"10.3390\/bios15100666","type":"journal-article","created":{"date-parts":[[2025,10,3]],"date-time":"2025-10-03T07:57:27Z","timestamp":1759478247000},"page":"666","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Development of Nanobody-Based Sandwich ELISA Resistant to SpA Interference for Sensitive Detection of Staphylococcal Enterotoxin A"],"prefix":"10.3390","volume":"15","author":[{"given":"Chenghao","family":"Hu","sequence":"first","affiliation":[{"name":"Department of Clinical Laboratory, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, China"},{"name":"Second School of Clinical Medicine, Jiangxi Medical College, Nanchang University, Nanchang 330031, China"},{"name":"National Engineering Research Center for Bioengineering Drugs and the Technologies, Jiangxi Provincial Key Laboratory of Bioengineering Drugs, Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang 330031, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Di","family":"Wang","sequence":"additional","affiliation":[{"name":"National Engineering Research Center for Bioengineering Drugs and the Technologies, Jiangxi Provincial Key Laboratory of Bioengineering Drugs, Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang 330031, China"},{"name":"Binzhou Center for Disease Control and Prevention, Binzhou 256002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yangwei","family":"Ou","sequence":"additional","affiliation":[{"name":"National Engineering Research Center for Bioengineering Drugs and the Technologies, Jiangxi Provincial Key Laboratory of Bioengineering Drugs, Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang 330031, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruoyu","family":"Li","sequence":"additional","affiliation":[{"name":"National Engineering Research Center for Bioengineering Drugs and the Technologies, Jiangxi Provincial Key Laboratory of Bioengineering Drugs, Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang 330031, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"Chen","sequence":"additional","affiliation":[{"name":"National Engineering Research Center for Bioengineering Drugs and the Technologies, Jiangxi Provincial Key Laboratory of Bioengineering Drugs, Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang 330031, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-5368-6861","authenticated-orcid":false,"given":"Peng","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"531","DOI":"10.2147\/IDR.S164278","article-title":"Characterization of enterotoxin A-producing Staphylococcus aureus","volume":"11","author":"Chen","year":"2018","journal-title":"Infect. 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