{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T03:42:15Z","timestamp":1790912535916,"version":"4.1.0"},"reference-count":28,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T00:00:00Z","timestamp":1764115200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["U2230132"],"award-info":[{"award-number":["U2230132"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"name":"open fund of Information Materials and Intelligent Sensing Laboratory of Anhui Province","award":["IMIS202209"],"award-info":[{"award-number":["IMIS202209"]}]},{"name":"Guiding Science and Technology Plan Project for Social Development in Zhenjiang City","award":["FZ2022052"],"award-info":[{"award-number":["FZ2022052"]}]},{"name":"Zhenjiang Science and Technology Plan","award":["SH2024098"],"award-info":[{"award-number":["SH2024098"]}]},{"name":"National Foreign Experts Program Project of China","award":["H20240553"],"award-info":[{"award-number":["H20240553"]}]},{"name":"Key Laboratory of Medicinal Animal and Plant Resources of Qinghai-Tibetan Plateau in Qinghai Province"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biosensors"],"abstract":"<jats:p>In recent years, the amount of mercury discharged by human activities has continued to increase. Most of the mercury in surface water settles into the sediment, where it can be directly or indirectly transformed into mercury ion (Hg2+) compounds (such as dimethylmercury) under the action of microorganisms. Hg2+ display high toxicity and bioaccumulation in food, such as fish and rice, and thus the contamination of mercury ion is a serious concern for human health. Practical Hg2+ detection methods are usually limited by the sensitivity and selectivity of the used methods, such as colorimetric determination and fluorescence biosensor based on the solution phase. Therefore, it is urgent to develop Hg2+ detection methods in the practical environment with high sensitivity and selectivity. DNA is low-cost, relatively stable, and has been used for different fields. In this study, DNA for Hg2+detection was absorbed on the surface of single-walled carbon nanotubes (SWNTs) by using 1,5-diaminonaphthalene (DAN) based on field-effect transistor (FET) biosensors. The interaction between DNA and Hg2+ can be directly converted into electrical signals based on the SWNTs biosensors. The experimental results showed that the limit of detection (LOD) of Hg2+ without the phase-locked amplifier was about 42.6 pM. The function of the phase-locked amplifier is to achieve fast detection of the biosensor with strong anti-noise ability. Intriguingly, the sensitivity of the biosensor combined with a phase-locked amplifier to detect Hg2+ was further improved to be 5.14 pM compared with some current methods of biosensors. Furthermore, this biosensor has an excellent selectivity and practical detection in tap water, which demonstrates its high performance and low cost in practical application in Hg2+ detection. These results show this method for Hg2+ detection using SWNTs biosensors with a phase-locked amplifier is promising.<\/jats:p>","DOI":"10.3390\/bios15120779","type":"journal-article","created":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T14:39:43Z","timestamp":1764167983000},"page":"779","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Ultra-Sensitive Detection of Mercury by Using Field-Effect Transistor Biosensors Based on Single-Walled Carbon Nanotubes"],"prefix":"10.3390","volume":"15","author":[{"given":"Chao","family":"Lu","sequence":"first","affiliation":[{"name":"Department of Medical Imaging, Jiangsu University Affiliated People\u2019s Hospital (Zhenjiang First People\u2019s Hospital), Zhenjiang 212002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiuxiang","family":"Lv","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Jiangsu University, Zhenjiang 212013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5293-1777","authenticated-orcid":false,"given":"Yuanwei","family":"Lin","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Jiangsu University, Zhenjiang 212013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Gao","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Jiangsu University, Zhenjiang 212013, China"},{"name":"School of Life Sciences, Qinghai Normal University, Xining 810000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,26]]},"reference":[{"key":"ref_1","first-page":"17287","article-title":"A multi-Well SERS chip for the detection of Hg2+","volume":"7","author":"Xing","year":"2024","journal-title":"ACS Appl. Appl. Appl. Nano Material"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"125105","DOI":"10.1016\/j.talanta.2023.125105","article-title":"Hg2+detection and information encryption of new [1+1] lanthanide cluster","volume":"26","author":"Yu","year":"2024","journal-title":"Talanta"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"135030","DOI":"10.1016\/j.snb.2023.135030","article-title":"Matrix redox interference-free nanozyme-amplified detection of Hg2+ using thiol-modified phosphatase-mimetic nanoceria","volume":"401","author":"Hu","year":"2024","journal-title":"Sens. Actuators B-Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"109561","DOI":"10.1016\/j.cclet.2024.109561","article-title":"Electrochemical aptasensor based on black phosphorus-porous graphene nanocomposites for high-performance detection of Hg2+","volume":"35","author":"Zhou","year":"2024","journal-title":"Chin. Chem. Lett."},{"key":"ref_5","unstructured":"(2025, October 10). European Parliament and Council of the European Union, Directive 2010\/75\/EU of the European Parliament and Council of 24 November 2010 on Industrial Emissions (Integrated Pollution Prevention and Control) (Recast), Available online: https:\/\/www.legislation.gov.uk\/eudr\/2010\/75."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"500","DOI":"10.1016\/j.talanta.2018.08.086","article-title":"The detection of mercury ion using DNA as sensors based on fluorescence resonance energy transfer","volume":"192","author":"Xia","year":"2019","journal-title":"Talanta"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"106524","DOI":"10.1016\/j.sab.2022.106524","article-title":"Facile green synthesis of magnetic porous organic polymers for fast preconcentration of trace lead andmercuryfrom environmental water followed by graphite urnace atomic absorption spectrometry detection","volume":"196","author":"Zhao","year":"2022","journal-title":"Spectrochim. Acta Part B-At. Spectrosc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"341223","DOI":"10.1016\/j.aca.2023.341223","article-title":"Metal ions-regulated chemical vapor generation of Hg2+: Mechanism and application in miniaturized point discharge atomic emission spectrometry assay of oxalate in clinical urolithiasis samples","volume":"1262","author":"Yang","year":"2023","journal-title":"Anal. Chim. Acta"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1250","DOI":"10.1021\/acsanm.2c04825","article-title":"Tracking silver nanoparticles during their synthesis by inductively coupled plasmamassspectrometry: Implications for colorimetric sensing of mercury ions","volume":"6","author":"Ilmiah","year":"2023","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Gao, L., Lv, Q., Xia, N., Lin, Y., Lin, F., and Han, B. (2021). Detection of mercury ion with high sensitivity and selectivity using a DNA\/graphene oxide hybrid immobilized on glass slides. Biosensors, 11.","DOI":"10.3390\/bios11090300"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2405212","DOI":"10.1002\/adfm.202405212","article-title":"Electrochemical and field effect transistor dual-mode biosensor chip for label-free detection of cytokine storm biomarker with high sensitivity within a wide range","volume":"34","author":"Ouyang","year":"2024","journal-title":"Adv. Funct. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2400716","DOI":"10.1002\/aelm.202400716","article-title":"Interfacial photogating of graphene field-effect transistor for photosensorybiomolecular detection","volume":"11","author":"Howe","year":"2025","journal-title":"Adv. Electron. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1007\/s00604-023-05814-y","article-title":"Label-free MXene-assisted field effect transistor for the determination of IL-6 in patients with kidney transplantation infection","volume":"190","author":"Li","year":"2023","journal-title":"Microchim. Acta"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"106778","DOI":"10.1016\/j.spmi.2020.106778","article-title":"A dual-gate field-effect transistor in graphene heterojunctions","volume":"150","author":"Guo","year":"2021","journal-title":"Superlattices Microstruct."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"136262","DOI":"10.1016\/j.snb.2024.136262","article-title":"Ultrasensitive graphene field-effect transistor biosensor for rapidly detecting miRNA-208a","volume":"418","author":"Hu","year":"2024","journal-title":"Sens. Actuators B-Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"7482","DOI":"10.1038\/s41467-024-51325-6","article-title":"Optimising CNT-FET biosensor design through modelling of biomolecular electrostatic gating and its application to \u03b2-lactamase detection","volume":"15","author":"Gwyther","year":"2024","journal-title":"Nat. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"28255","DOI":"10.1021\/acsanm.4c05198","article-title":"Advanced detection of SARS-CoV-2 and omicron variants via MXene-graphene hybrid biosensors utilizing nucleic acid probes","volume":"24","author":"Li","year":"2024","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Huang, K., Geng, Y., Zhang, X., Chen, D., Cai, Z., Wang, M., Zhu, Z., and Wang, Z. (2019). A wide-band digital lock-in amplifier and its application in microfluidic impedance measurement. Sensors, 19.","DOI":"10.3390\/s19163519"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"114710","DOI":"10.1063\/1.5125489","article-title":"A lock-in amplifier modeling recovery method to extract the surface nuclear magnetic resonance signal from residual noise","volume":"90","author":"Zhang","year":"2019","journal-title":"Rev. Sci. Instrum."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"341751","DOI":"10.1016\/j.aca.2023.341751","article-title":"Ultrasensitive detection and efficient removal of mercury ions based on covalent organic framework spheres with double active sites","volume":"1278","author":"Xiao","year":"2023","journal-title":"Anal. Chim. Acta"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1007\/s00604-019-4057-6","article-title":"Aggregation-based determination of mercury (II) using DNA-modified single gold nanoparticle, T-Hg (II)-T interaction, and single-particle ICP-MS","volume":"187","author":"Xing","year":"2019","journal-title":"Microchim. Acta"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Tu, J., Gan, Y., Liang, T., Hu, Q., Wang, Q., Ren, T., Sun, Q., Wan, H., and Wang, P. (2018). Graphene FET array biosensor based on ssDNA aptamer for ultrasensitive Hg2+ detection in environmental pollutants. Front. Chem., 6.","DOI":"10.3389\/fchem.2018.00333"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"23369","DOI":"10.1109\/JSEN.2024.3407528","article-title":"Highly sensitive detection of Hg2+ based on imprinting sensor modified DNA","volume":"24","author":"Dang","year":"2024","journal-title":"IEEE Sens. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1007\/s00604-023-05944-3","article-title":"Dual-ligand lanthanide metal-organic framework probe for ratiometric fluorescence detection of mercury ions in wastewater","volume":"190","author":"Wang","year":"2023","journal-title":"Microchim. Acta"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"4416","DOI":"10.1039\/C9AY01337G","article-title":"Highly sensitive detection of Hg2+ using covalent linking single-strand DNA to the surface of graphene oxide with co-anchor strand","volume":"11","author":"Gao","year":"2019","journal-title":"Anal. Methods"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"343283","DOI":"10.1016\/j.aca.2024.343283","article-title":"A novel dual-detection electrochemiluminescence sensor for the selective detection of Hg2+ and Zn2+: Signal suppression and activation mechanisms","volume":"1330","author":"Hu","year":"2024","journal-title":"Anal. Chim. Acta"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1007\/s10661-023-12217-2","article-title":"A multifunctional fluorescent sensor for Ag+ and Hg2+ detection in seawater","volume":"196","author":"Zhang","year":"2024","journal-title":"Environ. Monit. Assess."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1016\/j.bios.2014.04.022","article-title":"Electrochemical impedance spectroscopy aptasensor for ultrasensitive detection of adenosine with dual backfillers","volume":"60","author":"Wang","year":"2014","journal-title":"Biosens. Bioelectron."}],"container-title":["Biosensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6374\/15\/12\/779\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,29]],"date-time":"2025-11-29T05:13:57Z","timestamp":1764393237000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6374\/15\/12\/779"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,26]]},"references-count":28,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["bios15120779"],"URL":"https:\/\/doi.org\/10.3390\/bios15120779","relation":{},"ISSN":["2079-6374"],"issn-type":[{"value":"2079-6374","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,26]]}}}