{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T14:48:31Z","timestamp":1777474111708,"version":"3.51.4"},"reference-count":50,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2024,6,4]],"date-time":"2024-06-04T00:00:00Z","timestamp":1717459200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Major Instrumentation Development Program of the Chinese Academy of Sciences","award":["ZDKYYQ20220008"],"award-info":[{"award-number":["ZDKYYQ20220008"]}]},{"name":"Major Instrumentation Development Program of the Chinese Academy of Sciences","award":["2021B1515140018"],"award-info":[{"award-number":["2021B1515140018"]}]},{"name":"Guangdong Basic and Applied Basic Research Foundation","award":["ZDKYYQ20220008"],"award-info":[{"award-number":["ZDKYYQ20220008"]}]},{"name":"Guangdong Basic and Applied Basic Research Foundation","award":["2021B1515140018"],"award-info":[{"award-number":["2021B1515140018"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Quasi-bound state in the continuum (QBIC) can effectively enhance the interaction of terahertz (THz) wave with matter due to the tunable high-Q property, which has a strong potential application in the detection of low-concentration biological samples in the THz band. In this paper, a novel THz metamaterial sensor with a double-chain-separated resonant cavity structure based on QBIC is designed and fabricated. The process of excitation of the QBIC mode is verified and the structural parameters are optimized after considering the ohmic loss by simulations. The simulated refractive index sensitivity of the sensor is up to 544 GHz\/RIU, much higher than those of recently reported THz metamaterial sensors. The sensitivity of the proposed metamaterial sensor is confirmed in an experiment by detecting low-concentration lithium citrate (LC) and bovine serum albumin (BSA) solutions. The limits of detection (LoDs) are obtained to be 0.0025 mg\/mL (12 \u03bcM) for LC and 0.03125 mg\/mL (0.47 \u03bcM) for BSA, respectively, both of which excel over most of the reported results in previous studies. These results indicate that the proposed THz metamaterial sensor has excellent sensing performances and can well be applied to the detection of low-concentration biological samples.<\/jats:p>","DOI":"10.3390\/s24113649","type":"journal-article","created":{"date-parts":[[2024,6,5]],"date-time":"2024-06-05T03:49:28Z","timestamp":1717559368000},"page":"3649","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Detection of Low-Concentration Biological Samples Based on a QBIC Terahertz Metamaterial Sensor"],"prefix":"10.3390","volume":"24","author":[{"given":"Bing","family":"Dong","sequence":"first","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"},{"name":"College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China"}]},{"given":"Bo","family":"Wei","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3999-3911","authenticated-orcid":false,"given":"Dongshan","family":"Wei","sequence":"additional","affiliation":[{"name":"Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China"}]},{"given":"Zhilin","family":"Ke","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"}]},{"given":"Dongxiong","family":"Ling","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1186\/s43074-020-00011-z","article-title":"Terahertz spectroscopy in biomedical field: A review on signal-to-noise ratio improvement","volume":"1","author":"Peng","year":"2020","journal-title":"PhotoniX"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"D\u2019Arco, A., Di Fabrizio, M., Dolci, V., Petrarca, M., and Lupi, S. 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