{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T19:42:15Z","timestamp":1792784535015,"version":"4.5.0"},"reference-count":38,"publisher":"American Chemical Society (ACS)","issue":"37","license":[{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/501100003392","name":"Natural Science Foundation of Fujian Province","doi-asserted-by":"publisher","award":["2024J01809"],"award-info":[{"award-number":["2024J01809"]}],"id":[{"id":"10.13039\/501100003392","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Natural Science Foundation of Zhangzhou","award":["ZZ2025JH01"],"award-info":[{"award-number":["ZZ2025JH01"]}]},{"name":"Eagle Plan Project of Fujian Province"},{"name":"Principal Fund of Minnan Normal University","award":["KJ18014"],"award-info":[{"award-number":["KJ18014"]}],"id":[{"id":"https:\/\/ror.org\/02vj1vm13","id-type":"ROR","asserted-by":"crossref"}]},{"name":"National Natural Science Foundation of China (NSFC)","award":["22004054"],"award-info":[{"award-number":["22004054"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"crossref"}]},{"name":"National Natural Science Foundation of China (NSFC)","award":["22376089"],"award-info":[{"award-number":["22376089"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Urease serves as a key diagnostic biomarker, whose abnormal activity is closely associated with oral diseases such as caries and periodontitis. However, detecting trace urease in saliva remains technically challenging. In this work, we report for the first time a C4-rGO-FET biosensor by integrating a conformation-switchable C4-DNA probe with an electrochemically reduced graphene oxide field-effect transistor. The sensing mechanism relies on the pH-induced conformational transition of C4-DNA between a folded i-motif and an unfolded state, which effectively modulates the interfacial charge and thus the carrier distribution in the rGO channel, resulting in a measurable shift in the Dirac point voltage (VCNP). The designed sensor exhibits significantly enhanced pH response (51.57 mV\/pH) and reduces the Debye shielding effect. Upon urease-catalyzed hydrolysis of urea, the resulting local pH increase triggers a positive VCNP shift, enabling highly sensitive detection of urease activity. The biosensor demonstrates a wide linear range (1\u2013500 U\/L), a low detection limit (0.18 U\/L), and good reproducibility. Moreover, it performs reliably in spiked human saliva samples, highlighting its strong potential for point-of-care testing and real-time monitoring in clinical diagnostics.<\/jats:p>","DOI":"10.1021\/acs.analchem.6c02836","type":"journal-article","created":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T02:01:27Z","timestamp":1789092087000},"page":"27381-27390","source":"Crossref","is-referenced-by-count":0,"title":["An i-Motif\nConformational Transition Synergizing\nwith pH-Responsive Reduced Graphene Oxide Field-Effect Transistor\nfor Urease Activity Sensing"],"prefix":"10.1021","volume":"98","author":[{"given":"Huan","family":"Ju","sequence":"first","affiliation":[{"name":"Minnan Normal University , , ,","place":["Zhangzhou, China, 363000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiangna","family":"Ni","sequence":"additional","affiliation":[{"name":"Fujian Medical University Union Hospital , , ,","place":["Fuzhou, China, 350001"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanqi","family":"Tan","sequence":"additional","affiliation":[{"name":"Minnan Normal University , , ,","place":["Zhangzhou, China, 363000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhiping","family":"Song","sequence":"additional","affiliation":[{"name":"Minnan Normal University , , ,","place":["Zhangzhou, China, 363000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3621-687X","authenticated-orcid":true,"given":"Xiaoping","family":"Chen","sequence":"additional","affiliation":[{"name":"Minnan Normal University , , ,","place":["Zhangzhou, China, 363000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiancong","family":"Ni","sequence":"additional","affiliation":[{"name":"Minnan Normal University , , ,","place":["Zhangzhou, China, 363000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhenyu","family":"Lin","sequence":"additional","affiliation":[{"name":"Fuzhou University , , ,","place":["Fuzhou, China, 350116"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1224-0426","authenticated-orcid":true,"given":"Weiqiang","family":"Yang","sequence":"additional","affiliation":[{"name":"Minnan Normal University , , ,","place":["Zhangzhou, China, 363000"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,10]]},"reference":[{"key":"2026092208065216600_cit1","volume-title":"Ureases:\nFunctions, Classes, and Applications","author":"Braun","year":"2024"},{"key":"2026092208065216600_cit2","doi-asserted-by":"publisher","first-page":"485","DOI":"10.4155\/bio-2023-0207","article-title":"Enzymes as\nindispensable markers in disease diagnosis","volume":"16","author":"Pathan","year":"2024","journal-title":"Bioanalysis"},{"key":"2026092208065216600_cit3","doi-asserted-by":"publisher","first-page":"2302","DOI":"10.3748\/wjg.v30.i17.2302","article-title":"Evaluation\nof urea breath test as a diagnostic tool\nfor Helicobacter pylori infection in\nadult dyspeptic patients","volume":"30","author":"Said","year":"2024","journal-title":"World J. Gastroenterol."},{"issue":"9","key":"2026092208065216600_cit4","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms12091797","article-title":"Oral Microbiome: A\nReview of Its Impact on Oral and Systemic Health","volume":"12","author":"Rajasekaran","year":"2024","journal-title":"Microorganisms"},{"key":"2026092208065216600_cit5","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1016\/j.jobcr.2022.10.004","article-title":"Effect\nof salivary urea, pH and ureolytic microflora on dental calculus formation\nand its correlation with periodontal status","volume":"13","author":"D\u2019Souza","year":"2023","journal-title":"J. Oral. Biol. Craniofac."},{"key":"2026092208065216600_cit6","doi-asserted-by":"publisher","first-page":"3888","DOI":"10.1021\/acssensors.4c03091","article-title":"Predictive\nAnalysis of Dental Caries\nRisk via Rapid Urease Activity Evaluation in Saliva Using a ZIF-8\nNanoporous Membrane","volume":"10","author":"Zhou","year":"2025","journal-title":"ACS Sens."},{"key":"2026092208065216600_cit7","doi-asserted-by":"publisher","DOI":"10.1016\/j.talanta.2021.122301","article-title":"Paper-based\nanalytical device with colorimetric detection for urease activity\ndetermination in soils and evaluation of potential inhibitors","volume":"230","author":"Tavares","year":"2021","journal-title":"Talanta"},{"issue":"10","key":"2026092208065216600_cit8","doi-asserted-by":"publisher","DOI":"10.1007\/s00604-025-07496-0","article-title":"Smartphone-based\ncolorimetric detection\nof urease activity in dental plaque for point-of-care screening of Helicobacter pylori infection","volume":"192","author":"Wang","year":"2025","journal-title":"Microchim. 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J."},{"key":"2026092208065216600_cit37","doi-asserted-by":"publisher","first-page":"1072","DOI":"10.1016\/j.physa.2012.09.022","article-title":"The persistence length and length\nper base of single-stranded DNA obtained from fluorescence correlation\nspectroscopy measurements using mean field theory","volume":"392","author":"Chi","year":"2013","journal-title":"Physica A"},{"key":"2026092208065216600_cit38","doi-asserted-by":"publisher","first-page":"2820","DOI":"10.1016\/j.bpj.2013.10.021","article-title":"Structure and Mechanical\nCharacterization\nof DNA i-Motif Nanowires by Molecular Dynamics Simulation","volume":"105","author":"Singh","year":"2013","journal-title":"Biophys. 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