{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T13:22:14Z","timestamp":1774099334416,"version":"3.50.1"},"reference-count":50,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,1,21]],"date-time":"2024-01-21T00:00:00Z","timestamp":1705795200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science and Technology Planning Project of Guangzhou","award":["202102020782"],"award-info":[{"award-number":["202102020782"]}]},{"name":"Science and Technology Planning Project of Guangzhou","award":["51803037"],"award-info":[{"award-number":["51803037"]}]},{"name":"Leading Talents of Guangdong Province Program","award":["202102020782"],"award-info":[{"award-number":["202102020782"]}]},{"name":"Leading Talents of Guangdong Province Program","award":["51803037"],"award-info":[{"award-number":["51803037"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Diabetes patients need to monitor blood glucose all year round. In this article, a novel scheme is proposed for blood glucose detection. The proposed sensor is based on a U-shaped microfiber prepared using hydrogen-oxygen flame-heating technology, and then 3-aminopropyltriethoxysilane (APTES) and glucose oxidase (GOD) are successively coated on the surface of the U-shaped microfiber via a coating technique. The glucose reacts with the GOD of the sensor surface to produce gluconic acid, which changes the effective refractive index and then shifts the interference wavelength. The structure and morphology of the sensor were characterized via scanning electron microscope (SEM) and confocal laser microscopy (CLM). The experimental results show that the sensitivity of the sensor is as high as 5.73 nm\/(mg\/mL). Compared with the glucose sensor composed of the same material, the sensitivity of the sensor increased by 329%. The proposed sensor has a broad application prospect in blood glucose detection of diabetic patients due to the advantages of miniaturization, high sensitivity, and good stability.<\/jats:p>","DOI":"10.3390\/s24020684","type":"journal-article","created":{"date-parts":[[2024,1,22]],"date-time":"2024-01-22T12:01:13Z","timestamp":1705924873000},"page":"684","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["A Small Highly Sensitive Glucose Sensor Based on a Glucose Oxidase-Modified U-Shaped Microfiber"],"prefix":"10.3390","volume":"24","author":[{"given":"Tingkuo","family":"Chen","sequence":"first","affiliation":[{"name":"State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haiming","family":"Jiang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kang","family":"Xie","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hongyan","family":"Xia","sequence":"additional","affiliation":[{"name":"Department of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"123695","DOI":"10.1016\/j.talanta.2022.123695","article-title":"Wearable hollow microneedle sensing patches for the transdermal electrochemical monitoring of glucose","volume":"249","author":"Parrilla","year":"2022","journal-title":"Talanta"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"13952","DOI":"10.1021\/jacs.6b07331","article-title":"Bisboronic acids for selective, physiologically relevant direct glucose sensing with surfaceenhanced Raman spectroscopy","volume":"138","author":"Sharma","year":"2016","journal-title":"J. Am. Chem. Soc."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4697","DOI":"10.1039\/C7CS00837F","article-title":"Nanomaterial-based devices for point-of-care diagnostic applications","volume":"47","year":"2018","journal-title":"Chem. Soc. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"7927","DOI":"10.1039\/D1TB01403J","article-title":"Review on recent progress in metal-organic framework-based materials for fabricating electrochemical glucose sensors","volume":"9","author":"Gorle","year":"2021","journal-title":"J. Mater. Chem. B"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"944428","DOI":"10.3389\/fchem.2022.944428","article-title":"Electrospun nanofiber-based glucose sensors for glucose detection","volume":"10","author":"Du","year":"2022","journal-title":"Front. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.snb.2014.10.140","article-title":"Synthesis and characterization of nickel oxide hollow spheres\u2013reduced graphene oxide\u2013nafion composite and its biosensing for glucose","volume":"208","author":"Lu","year":"2015","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1016\/j.bios.2018.06.042","article-title":"Fiber-optic surface plasmon resonance glucose sensor enhanced with phenylboronic acid modified Au nanoparticles","volume":"117","author":"Yuan","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Zheng, W.L., Zhang, Y.N., Li, L.K., Li, X.G., and Zhao, Y. (2022). A plug-and-play optical fiber SPR sensor for simultaneous measurement of glucose and cholesterol concentrations. Biosens. Bioelectron., 198.","DOI":"10.1016\/j.bios.2021.113798"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Tang, S., Zou, M., Zhao, C., Jiang, Y., Chen, R., Xu, Z., Yang, C., Wang, X., Dong, B., and Wang, Y. (2022). Fabry-Perot Interferometer Based on a Fiber-Tip Fixed-Supported Bridge for Fast Glucose Concentration Measurement. Biosensors, 12.","DOI":"10.3390\/bios12060391"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Fang, Y.L., Wang, C.T., and Chiang, C.C. (2016). A Small U-Shaped Bending-Induced Interference Optical Fiber Sensor for the Measurement of Glucose Solutions. Sensors, 16.","DOI":"10.3390\/s16091460"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106981","DOI":"10.1016\/j.optlastec.2021.106981","article-title":"Optical fiber sensors for glucose concentration measurement: A review","volume":"139","author":"Gong","year":"2021","journal-title":"Opt. Laser Technol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Kaur, B., Kumar, S., and Kaushik, B.K. (2022). Recent advancements in optical biosensors for cancer detection. Biosens. Bioelectron., 197.","DOI":"10.1016\/j.bios.2021.113805"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"12930","DOI":"10.1364\/OE.423307","article-title":"No-core optical fiber sensor based on surface plasmon resonance for glucose solution concentration and temperature measurement","volume":"29","author":"Li","year":"2021","journal-title":"Opt. Express"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Raziq, A., Kidakova, A., Boroznjak, R., Reut, J., \u00d6pik, A., and Syritski, V. (2021). Development of a portable MIP-based electrochemical sensor for detection of SARS-CoV-2 antigen. Biosens. Bioelectron., 178.","DOI":"10.1016\/j.bios.2021.113029"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"16180","DOI":"10.1021\/acsnano.0c08494","article-title":"Emerging Telemedicine Tools for Remote COVID-19 Diagnosis, Monitoring, and Management","volume":"14","author":"Lukas","year":"2020","journal-title":"ACS Nano"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2100020","DOI":"10.1002\/admt.202100020","article-title":"Trending Technology of Glucose Monitoring during COVID-19 Pandemic: Challenges in Personalized Healthcare","volume":"6","author":"Phan","year":"2021","journal-title":"Adv. Mater. Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"14578","DOI":"10.1109\/JSEN.2020.3011173","article-title":"Theoretical Model and Design Considerations of U-Shaped Fiber Optic Sensors: A Review","volume":"20","author":"Tan","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1580","DOI":"10.1109\/JLT.2019.2958044","article-title":"Investigating the refractive index sensitivity of U-bent fiber optic sensors using ray optics","volume":"38","author":"Danny","year":"2020","journal-title":"J. Light. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4013","DOI":"10.1109\/JLT.2020.3027769","article-title":"Ultrasensitive Label-Free Biosensor Based on the Graphene-Oxide-Coated-U-Bent Long-Period Fiber Grating Inscribed in a Two-Mode Fiber","volume":"39","author":"Dong","year":"2021","journal-title":"J. Light. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1557","DOI":"10.1109\/JLT.2020.3034563","article-title":"A U-Shape Fibre-Optic pH Sensor Based on Hydrogen Bonding of Ethyl Cellulose with a Sol-Gel Matrix","volume":"39","author":"Tang","year":"2021","journal-title":"J. Light. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.optlastec.2019.01.045","article-title":"High sensitive applied load measurement using optical fiber tapered-loop probe with SPR effect","volume":"114","author":"Wu","year":"2019","journal-title":"Opt. Laser Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/S0925-4005(01)00995-9","article-title":"Fabrication and characterization of U-shaped fiber-optic pH probes","volume":"82","author":"Gupta","year":"2002","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Wen, H.Y., Hsu, H.C., Tsai, Y.T., Feng, W.K., Lin, C.L., and Chiang, C.C. (2021). U-Shaped Optical Fiber Probes Coated with Electrically Doped GQDs for Humidity Measurements. Polymers, 13.","DOI":"10.3390\/polym13162696"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2002206","DOI":"10.1002\/adom.202002206","article-title":"Self-Assembled Wavy Optical Microfiber for Stretchable Wearable Sensor","volume":"9","author":"Zhu","year":"2021","journal-title":"Adv. Opt. Mater."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"628","DOI":"10.1016\/j.sna.2018.12.005","article-title":"U-shaped microfiber coupler coated with polyvinyl alcohol film for highly sensitive humidity detection","volume":"285","author":"Zhao","year":"2019","journal-title":"Sensors Actuat. A Phys."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"133203","DOI":"10.1016\/j.snb.2022.133203","article-title":"U-shaped microfiber sensor coated with PVA nanofibers for the simultaneous measurement of humidity and temperature","volume":"378","author":"Chen","year":"2023","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1016\/j.snb.2018.02.123","article-title":"Humidity sensor based on unsymmetrical U-shaped microfiber with apolyvinyl alcohol overlay","volume":"263","author":"Zhao","year":"2018","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1016\/j.snb.2019.04.017","article-title":"Humidity sensor based on unsymmetrical U-shaped twisted microfiber coupler with wide detection range","volume":"290","author":"Peng","year":"2019","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6308","DOI":"10.1109\/JLT.2021.3096505","article-title":"U-shape panda polarization-maintaining microfiber sensor coated with graphene oxide for relative humidity measurement","volume":"39","author":"Chen","year":"2021","journal-title":"J. Light. Technol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"952","DOI":"10.1364\/OL.480724","article-title":"Dual-channel in-fiber SPR sensor for simultaneous and highly sensitive measurement of salinity and temperature","volume":"48","author":"Li","year":"2023","journal-title":"Opt. Lett."},{"key":"ref_31","first-page":"1095","article-title":"Microstructured Optical Fiber-Enhanced Light-Matter Interaction Enables Highly Sensitive Exosome-Based Liquid Biopsy of Breast Cancer","volume":"95","author":"Liu","year":"2023","journal-title":"Anal. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"128004","DOI":"10.1016\/j.snb.2020.128004","article-title":"Whispering gallery mode resonator and glucose oxidase based glucose biosensor","volume":"318","author":"Brice","year":"2020","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.snb.2019.02.083","article-title":"Metal-organic framework\/enzyme coated optical fibers as waveguide-based biosensors","volume":"288","author":"Zhu","year":"2019","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Chen, K.C., Li, Y.L., Wu, C.W., and Chiang, C.C. (2018). Glucose Sensor Using U-Shaped Optical Fiber Probe with Gold Nanoparticles and Glucose Oxidase. Sensors, 18.","DOI":"10.3390\/s18041217"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4805","DOI":"10.1039\/c1cs15063d","article-title":"Optical methods for sensing glucose","volume":"40","author":"Steiner","year":"2011","journal-title":"Chem. Soc. Rev."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1016\/j.bios.2011.12.051","article-title":"Immobilization of enzyme on long period grating fibers for sensitive glucose detection","volume":"33","author":"Deep","year":"2012","journal-title":"Biosens. Bioelectron."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Yu, S., Ding, L., Lin, H., Wu, W., and Huang, J. (2019). A novel optical fiber glucose biosensor based on carbon quantum dots-glucose oxidase\/cellulose acetate complex sensitive film. Biosens. Bioelectron., 146.","DOI":"10.1016\/j.bios.2019.111760"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"110329","DOI":"10.1016\/j.msec.2019.110329","article-title":"Graphene oxide-functionalized long period fiber grating for ultrafast labelfree glucose biosensor","volume":"107","author":"Xu","year":"2020","journal-title":"Mat. Sci. Eng. C Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"131984","DOI":"10.1016\/j.snb.2022.131984","article-title":"Optical fiber SPR biosensor with a solid-phase enzymatic reaction device for glucose detection","volume":"366","author":"Zhang","year":"2022","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Ran, Y., Long, J., Xu, Z., Yin, Y., Hu, D., Long, X., Zhang, Y., Liang, L., Liang, H., and Guan, B.O. (2022). Harmonic optical microfiber Bragg grating immunosensor for the accelerative test of cardiac biomarker (cTn-I). Biosens. Bioelectron., 179.","DOI":"10.1016\/j.bios.2021.113081"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"30571","DOI":"10.1364\/OE.22.030571","article-title":"Novel glucose sensor based on enzyme-immobilized 81\u00b0 tilted fiber grating","volume":"22","author":"Luo","year":"2014","journal-title":"Opt. Express"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3884","DOI":"10.1364\/OE.25.003884","article-title":"Investigation for terminal reflection optical fiber SPR glucose sensor and glucose sensitive membrane with immobilized GODs","volume":"25","author":"Yuan","year":"2017","journal-title":"Opt. Express"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"105010","DOI":"10.1016\/j.microc.2020.105010","article-title":"Highly-sensitive and reflective glucose sensor based on optical fiber surface plasmon resonance","volume":"157","author":"Zheng","year":"2020","journal-title":"Microchem. J."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2756","DOI":"10.1109\/JLT.2018.2878762","article-title":"Label-Free Thrombin Detection Using a Tapered Fiber-Optic Interferometric Aptasensor","volume":"37","author":"Sun","year":"2019","journal-title":"J. Light. Technol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"130245","DOI":"10.1016\/j.matlet.2021.130245","article-title":"Relative humidity sensor based on U-shaped microfiber interferometer coated with MoS2 films","volume":"301","author":"Li","year":"2021","journal-title":"Mater. Lett."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Huang, Y., Chen, P., Liang, H., Xiao, A., Zeng, S., and Guan, B.O. (2020). Nucleic acid hybridization on a plasmonic nanointerface of optical microfiber enables ultrahigh-sensitive detection and potential photothermal therapy. Biosens. Bioelectron., 156.","DOI":"10.1016\/j.bios.2020.112147"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3896","DOI":"10.1109\/JLT.2020.3028307","article-title":"Graphitic Carbon Nitride for Enhancing Humidity Sensing of Microfibers","volume":"39","author":"Yan","year":"2021","journal-title":"J. Light. Technol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"3004","DOI":"10.1016\/j.snb.2017.09.123","article-title":"Immobilized optical fiber microprobe for selective and high sensitiveglucose detection","volume":"255","author":"Li","year":"2018","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1033","DOI":"10.1016\/j.snb.2017.07.109","article-title":"Label-free glucose biosensor based on enzymatic grapheneoxide-functionalized tilted fiber grating","volume":"254","author":"Jiang","year":"2018","journal-title":"Sensors Actuat. B. Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"21046","DOI":"10.1364\/OE.395524","article-title":"In-situ dual-channel surface plasmon resonance fiber sensor for temperature-compensated detection of glucose concentration","volume":"28","author":"Wu","year":"2020","journal-title":"Opt. Express"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/2\/684\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T13:46:47Z","timestamp":1760104007000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/2\/684"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,1,21]]},"references-count":50,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2024,1]]}},"alternative-id":["s24020684"],"URL":"https:\/\/doi.org\/10.3390\/s24020684","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,1,21]]}}}