{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T18:15:50Z","timestamp":1783361750691,"version":"3.54.6"},"reference-count":40,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T00:00:00Z","timestamp":1783296000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>This study presents a triple-band perfect metamaterial absorber with a compact microstructured design, achieving near-unity absorption rates of 99.92%, 99.97%, and 99.58% at three distinct terahertz resonance frequencies of 0.925 THz, 1.71 THz, and 2.7675 THz, respectively, for advanced biomedical biosensing applications. The work represents a theoretical and numerical proof-of-concept investigation based on full-wave electromagnetic simulations and refractive-index-assisted biosensing analysis, demonstrating the feasibility of high-sensitivity terahertz detection of biological analytes. The proposed absorber consists of concentric copper ring resonators combined with a central 7-shaped snowflake pattern, developed on an FR-4 dielectric substrate and backed by a continuous copper ground plane. Numerical simulations using the FDTD method were combined with a genetic algorithm approach, enabling the design of high-performance terahertz metamaterials, yielding three sharp, high-Q resonances with near-perfect absorption and ultra-narrow linewidths characteristics. The proposed sensor also demonstrates excellent capabilities including breast cancer cell identification with peak sensitivity of 10,142.86 GHz\/RIU, infectious agent recognition, and polarization insensitivity over 0\u201390\u00b0, alongside enhanced absorption tolerance that supports clinical deployment. To evaluate biosensing capability, refractive-index-assisted numerical modeling was performed using literature-reported dielectric properties of biological analytes, including cancer cells, viruses, glucose concentrations, blood components, intracellular materials, and biological tissues. The proposed sensor achieves a maximum sensitivity of 529 GHz\/RIU at the third resonance mode with strong linear resonance shifts and high spectral selectivity. Owing to its multi-band terahertz sensor facilitates and strong confinement of electric and magnetic fields at the resonant frequencies enhances the device\u2019s sensitivity to minimal changes in the surrounding medium, allowing for precise, label-free detection of biological analytes including viral variants, malaria pathogens, glucose concentrations, hemoglobin elements, classification of diabetes severity and can also differentiate in anemia categorization across diverse biomedical applications.<\/jats:p>","DOI":"10.1371\/journal.pone.0342575","type":"journal-article","created":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T17:31:56Z","timestamp":1783359116000},"page":"e0342575","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["A triple-band terahertz metamaterial perfect absorber for biomedical applications and biomarker detection"],"prefix":"10.1371","volume":"21","author":[{"given":"Mohammad Mahmudul Alam","family":"Mia","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Md. 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Singh","year":"2025","journal-title":"Optik"},{"issue":"1","key":"pone.0342575.ref020","doi-asserted-by":"crossref","first-page":"232","DOI":"10.3390\/s25010232","article-title":"A refractive index-based dual-band metamaterial sensor design and analysis for biomedical sensing applications","volume":"25","author":"L Darsi","year":"2025","journal-title":"Sensors (Basel)"},{"key":"pone.0342575.ref021","doi-asserted-by":"crossref","first-page":"117797","DOI":"10.1016\/j.sna.2026.117797","article-title":"Terahertz multiband metamaterial biosensor for ultrasensitive detection of PC-12 adrenal gland carcinoma cells through microenvironmental analysis","volume":"405","author":"MN Hamza","year":"2026","journal-title":"Sens Actuators A: Phys"},{"key":"pone.0342575.ref022","doi-asserted-by":"crossref","first-page":"108426","DOI":"10.1016\/j.optlaseng.2024.108426","article-title":"Modelling and analysis of a triple-band metamaterial absorber for early-stage cervical cancer HeLa cell detection","volume":"181","author":"SMA Haque","year":"2024","journal-title":"Opt Lasers Eng"},{"issue":"1","key":"pone.0342575.ref023","doi-asserted-by":"crossref","first-page":"100514","DOI":"10.1016\/j.kjs.2025.100514","article-title":"High-efficiency multi-band metamaterial absorber for X to Ka band applications","volume":"53","author":"KSL Al-Badri","year":"2026","journal-title":"Kuwait J Sci"},{"issue":"23","key":"pone.0342575.ref024","article-title":"Tutorial: an introduction to terahertz time domain spectroscopy (THz-TDS)","volume":"124","author":"J Neu","year":"2018","journal-title":"J Appl Phys"},{"key":"pone.0342575.ref025","first-page":"157","volume-title":"Optical metamaterials fundamentals and application","author":"W Cai","year":"2010"},{"key":"pone.0342575.ref026","article-title":"Designing the cavity architecture in double gate junctionless field effect transistor for enhanced biomolecule detection","author":"S Khan","year":"2025","journal-title":"Nanoscale Adv"},{"issue":"4","key":"pone.0342575.ref027","doi-asserted-by":"crossref","first-page":"765","DOI":"10.3390\/ma18040765","article-title":"Terahertz metamaterial absorber and equivalent circuit model for refractive index sensing","volume":"18","author":"Z Lu","year":"2025","journal-title":"Materials (Basel)"},{"key":"pone.0342575.ref028","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.sbsr.2017.02.002","article-title":"Effect of biomolecule position and fill in factor on sensitivity of a Dielectric Modulated Double Gate Junctionless MOSFET biosensor","volume":"13","author":"E Rahman","year":"2017","journal-title":"Sens Bio-Sens Res"},{"issue":"4","key":"pone.0342575.ref029","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/JPHOT.2019.2924825","article-title":"Surface plasmon resonance based titanium coated biosensor for cancer cell detection","volume":"11","author":"MA Jabin","year":"2019","journal-title":"IEEE Photonics J"},{"key":"pone.0342575.ref030","doi-asserted-by":"crossref","unstructured":"Hassan MdF, Tathfif I, Radoan M, Sagor RH. A concentric double-ring resonator based plasmonic refractive index sensor with glucose sensing capability. 2020 IEEE Region 10 Conference (Tencon); 2020. p. 91\u20136. https:\/\/doi.org\/10.1109\/tencon50793.2020.9293901","DOI":"10.1109\/TENCON50793.2020.9293901"},{"issue":"8","key":"pone.0342575.ref031","doi-asserted-by":"crossref","first-page":"2164","DOI":"10.1364\/OSAC.433633","article-title":"Detection of hemoglobin in blood and urine glucose level samples using a graphene-coated SPR based biosensor","volume":"4","author":"S Mostufa","year":"2021","journal-title":"OSA Continuum"},{"issue":"9","key":"pone.0342575.ref032","doi-asserted-by":"crossref","first-page":"3499","DOI":"10.1007\/s00542-020-05193-x","article-title":"Analysis of integrated silicon nitride lab-on-a-chip optofluidic sensor at visible wavelength for absorbance based biosensing applications","volume":"27","author":"M Kumar","year":"2021","journal-title":"Microsyst Technol"},{"issue":"16","key":"pone.0342575.ref033","doi-asserted-by":"crossref","first-page":"3235","DOI":"10.1364\/AO.49.003235","article-title":"Complex refractive index measurement of biological tissues by attenuated total reflection ellipsometry","volume":"49","author":"J-C Lai","year":"2010","journal-title":"Appl Opt"},{"issue":"7","key":"pone.0342575.ref034","doi-asserted-by":"crossref","DOI":"10.1101\/pdb.prot5455","article-title":"Homogenization of mammalian tissue","volume":"2010","author":"RJ Simpson","year":"2010","journal-title":"Cold Spring Harb Protoc"},{"issue":"3","key":"pone.0342575.ref035","doi-asserted-by":"crossref","first-page":"259","DOI":"10.4161\/cbt.3.3.694","article-title":"Spectroscopic sensing of cancer and cancer therapy: current status of translational research","volume":"3","author":"IJ Bigio","year":"2004","journal-title":"Cancer Biol Ther"},{"issue":"2","key":"pone.0342575.ref036","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/0002-9343(79)90538-2","article-title":"Plasma erythropoietin in polycythemia","volume":"66","author":"AJ Erslev","year":"1979","journal-title":"Am J Med"},{"key":"pone.0342575.ref037","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1007\/978-1-4615-7133-9_18","article-title":"Guiding principles of specimen preservation for confocal fluorescence microscopy.","volume-title":"Handbook of biological confocal microscopy","author":"R Bacallao","year":"1990"},{"issue":"5","key":"pone.0342575.ref038","doi-asserted-by":"crossref","first-page":"2686","DOI":"10.1007\/s11664-024-10999-w","article-title":"A dual-band terahertz metamaterial absorber using an all-metal aluminum hexagonal metasurface structure for sensing of cancerous cells","volume":"53","author":"A Teber","year":"2024","journal-title":"J Electron Mater"},{"issue":"10","key":"pone.0342575.ref039","doi-asserted-by":"crossref","first-page":"777","DOI":"10.3390\/photonics9100777","article-title":"Sensing performance of triple-band terahertz metamaterial absorber based on snowflake-shaped resonators","volume":"9","author":"L Ma","year":"2022","journal-title":"Photonics"},{"issue":"2","key":"pone.0342575.ref040","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1109\/TPS.2025.3531426","article-title":"Skin cancer detection using terahertz metamaterial absorber and machine learning","volume":"53","author":"S Banerjee","year":"2025","journal-title":"IEEE Trans Plasma Sci"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0342575","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T17:32:17Z","timestamp":1783359137000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0342575"}},"subtitle":[],"editor":[{"given":"Mallikarjuna Reddy","family":"Kesama","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,7,6]]},"references-count":40,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7,6]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0342575","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,6]]}}}