{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T23:38:55Z","timestamp":1792193935265,"version":"4.4.0"},"reference-count":47,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2025,3,31]],"date-time":"2025-03-31T00:00:00Z","timestamp":1743379200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Shandong Engineering Technology Research Laboratory of Suzhou Biomedical Engineering and Technology of Chinese Academy of Sciences","award":["YCSKY202109058C1"],"award-info":[{"award-number":["YCSKY202109058C1"]}]},{"name":"Shandong Engineering Technology Research Laboratory of Suzhou Biomedical Engineering and Technology of Chinese Academy of Sciences","award":["2024TSGC0159"],"award-info":[{"award-number":["2024TSGC0159"]}]},{"name":"Shandong Engineering Technology Research Laboratory of Suzhou Biomedical Engineering and Technology of Chinese Academy of Sciences","award":["22176209"],"award-info":[{"award-number":["22176209"]}]},{"name":"Key R&amp;D Program of Shandong Province, China","award":["YCSKY202109058C1"],"award-info":[{"award-number":["YCSKY202109058C1"]}]},{"name":"Key R&amp;D Program of Shandong Province, China","award":["2024TSGC0159"],"award-info":[{"award-number":["2024TSGC0159"]}]},{"name":"Key R&amp;D Program of Shandong Province, China","award":["22176209"],"award-info":[{"award-number":["22176209"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["YCSKY202109058C1"],"award-info":[{"award-number":["YCSKY202109058C1"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2024TSGC0159"],"award-info":[{"award-number":["2024TSGC0159"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22176209"],"award-info":[{"award-number":["22176209"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biosensors"],"abstract":"<jats:p>Herein, we proposed a versatile G-quadruplex (G4)-tetrahedral DNA framework (G4-TDF) nanostructure functionalized origami microfluidic paper-based device (\u03bcPADs) for fluorescence detection of K+ by lighting up thioflavin T (ThT). In this work, TDF provided robust structural support for G-rich sequence in well-defined orientation and spacing to ensure high recognition efficiency, enabling sensitive fluorescence sensing on origami \u03bcPAD. After introducing ThT, the G-rich sequences extended from TDF vertices formed a parallel G4 structure, showing weak fluorescence signal output. Upon the presence of target K+, this parallel G4 structure transitioned to antiparallel G4 structure, leading to a significantly increase in fluorescence signal of ThT. Benefiting from the outstanding fluorescence enhancement characteristic of the G4 structure for ThT and excellent specificity of the G4 structure to K+ plus satisfactory recognition efficiency with the aid of TDF, this origami paper-based fluorescence sensing strategy exhibited an impressive detection limit as low as 0.2 mM with a wide range of 0.5\u20135.5 mM. This innovative G4-TDF fluorescence sensing was applied for the first time on \u03bcPAD, providing a simple, effective, and rapid method for K+ detection in human serum with significant potential for clinical diagnostics.<\/jats:p>","DOI":"10.3390\/bios15040223","type":"journal-article","created":{"date-parts":[[2025,4,1]],"date-time":"2025-04-01T03:24:58Z","timestamp":1743477898000},"page":"223","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Intermolecular Structure Conversion-Based G4-TDF Nanostructures Functionalized \u03bcPADs for Fluorescent Determination of Potassium Ion in Serum"],"prefix":"10.3390","volume":"15","author":[{"given":"Mengqi","family":"Wang","sequence":"first","affiliation":[{"name":"School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiuli","family":"Fu","sequence":"additional","affiliation":[{"name":"School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yixuan","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhiyang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Coastal Zone Ecological Environment Monitoring Technology and Equipment Shan-dong Engineering Research Center, Shandong Key Laboratory of Coastal Environ-mental Processes, CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chenyu","family":"Jiang","sequence":"additional","affiliation":[{"name":"Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1951-0839","authenticated-orcid":false,"given":"Dean","family":"Song","sequence":"additional","affiliation":[{"name":"Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"11121","DOI":"10.1021\/acs.jafc.0c05139","article-title":"Rise in potassium deficiency in the US population linked to agriculture practices and dietary potassium deficits","volume":"68","author":"Sun","year":"2020","journal-title":"J. Agric. Food Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1038\/s41467-019-13834-7","article-title":"Ionophore constructed from non-covalent assembly of a G-quadruplex and liponucleoside transports K+-ion across biological membranes","volume":"11","author":"Debnath","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1016\/j.bios.2014.05.052","article-title":"Development of an electrochemical sensor based on the catalysis of ferrocene actuated hemin\/G-quadruplex enzyme for the detection of potassium ions","volume":"61","author":"Wang","year":"2014","journal-title":"Biosens. Bioelectron."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.semnephrol.2013.04.004","article-title":"Extracellular potassium homeostasis: Insights from hypokalemic periodic paralysis","volume":"33","author":"Cheng","year":"2013","journal-title":"Semin. Nephrol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"134008","DOI":"10.1016\/j.snb.2023.134008","article-title":"Cross-conjugated polymers as fluorescent probes for intracellular potassium ion detection","volume":"390","author":"Wang","year":"2023","journal-title":"Sens. Actuators B"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"8018","DOI":"10.1039\/C4AY01025F","article-title":"A simple colorimetric sensor for potassium ion based on DNA G-quadruplex conformation and salt-induced gold nanoparticles aggregation","volume":"6","author":"Chen","year":"2014","journal-title":"Anal. Methods"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.1515\/cclm-2016-0803","article-title":"A candidate reference method for serum potassium measurement by inductively coupled plasma mass spectrometry","volume":"55","author":"Yan","year":"2017","journal-title":"Clin. Chem. Lab. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.nima.2017.01.064","article-title":"The quick and ultrasensitive determination of K in NaI using inductively coupled plasma mass Spectrometry","volume":"851","author":"Arnquist","year":"2017","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A"},{"key":"ref_9","first-page":"99","article-title":"Estimation of uncertainty in the determination of serum electrolytes (Na, K, Ca, Mg) by flame atomic absorption spectroscopy","volume":"33","year":"2018","journal-title":"MAPAN-J. Metrol. Soc. I."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3754","DOI":"10.1021\/acs.analchem.5b04610","article-title":"Tunable diode laser atomic absorption spectroscopy for detection of potassium under optically thick conditions","volume":"88","author":"Qu","year":"2016","journal-title":"Anal. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"111401","DOI":"10.1016\/j.apradiso.2024.111401","article-title":"Determination of chemical elements of barley and teff using flame atomic absorption spectroscopy (FAAS)","volume":"211","author":"Messele","year":"2024","journal-title":"Appl. Radiat. Isot."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1420","DOI":"10.1007\/s12161-019-01478-8","article-title":"Fast sequential determination of Zn, Fe, Mg, Ca, Na, and K in infant formulas by high-resolution continuum source flame atomic absorption spectrometry using ultrasound-assisted extraction","volume":"12","author":"Gamela","year":"2019","journal-title":"Food Anal. Methods"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1016\/S0925-4005(03)00599-9","article-title":"K+-ion sensing using surface plasmon resonance by NIR light source","volume":"96","author":"Eum","year":"2003","journal-title":"Sens. Actuators B"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"96","DOI":"10.3390\/toxins6010096","article-title":"Surface plasmon resonance biosensor method for palytoxin detection based on Na+,K+-ATPase affinity","volume":"6","author":"Alfonso","year":"2014","journal-title":"Toxins"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"132055","DOI":"10.1016\/j.foodchem.2022.132055","article-title":"Open tubular capillary ion chromatography with online dilution for small ions determination in drinks","volume":"382","author":"Kanyanee","year":"2022","journal-title":"Food Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1080\/10826076.2015.1128443","article-title":"Research onto the contents of selected inorganic ions in the dialysis fluids and dialysates by using ion chromatography","volume":"39","author":"Michalski","year":"2016","journal-title":"J. Liq. Chromatogr. Relat. Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"12181","DOI":"10.1021\/acs.analchem.4c02389","article-title":"A programmable microfluidic paper-based analytical device for simultaneous colorimetric and photothermal visual sensing of multiple enzyme activities","volume":"96","author":"Li","year":"2024","journal-title":"Anal. Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"41194","DOI":"10.1021\/acsomega.3c04387","article-title":"Dual chromatic laser-printed microfluidic paper-based analytical device (\u03bcPAD) for the detection of atrazine in water","volume":"8","author":"Moulahoum","year":"2023","journal-title":"ACS Omega"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1007\/s13206-020-4407-9","article-title":"Simultaneous multiplexed detection of protein and metal ions by a colorimetric microfluidic paper-based analytical device","volume":"14","author":"Xiong","year":"2020","journal-title":"BioChip J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"46317","DOI":"10.1021\/acsami.1c12716","article-title":"Electrochemical microfluidic paper-based aptasensor platform based on a biotin\u2013streptavidin system for label-free detection of biomarkers","volume":"13","author":"Ming","year":"2021","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Zhuang, J.W., Zhao, Z.Y., Lian, K., Yin, L.J., Wang, J.J., Man, S.L., Liu, G.Z., and Ma, L. (2022). SERS-based CRISPR\/Cas assay on microfluidic paper analytical devices for supersensitive detection of pathogenic bacteria in foods. Biosens. Bioelectron., 207.","DOI":"10.1016\/j.bios.2022.114167"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"133735","DOI":"10.1016\/j.jhazmat.2024.133735","article-title":"All-in-one strategy for the nano-engineering of paper-based bifunctional fluorescent platform for robustly-integrated real-time monitoring of food and drinking-water safety","volume":"467","author":"Jiang","year":"2024","journal-title":"J. Hazard. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"5459","DOI":"10.1021\/acs.analchem.0c05134","article-title":"Ultrasensitive microfluidic paper-based electrochemical\/visual analytical device via signal amplification of Pd@hollow Zn\/Co core\u2013shell ZIF67\/ZIF8 nanoparticles for prostate-specific antigen detection","volume":"93","author":"Zhou","year":"2021","journal-title":"Anal. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.bios.2019.04.043","article-title":"Signal amplification strategies for paper-based analytical devices","volume":"136","author":"Liu","year":"2019","journal-title":"Biosens. Bioelectron."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"117607","DOI":"10.1016\/j.saa.2019.117607","article-title":"A label-free G-quadruplex-based fluorescence assay for sensitive detection of alkaline phosphatase with the assistance of Cu2+","volume":"227","author":"Ma","year":"2020","journal-title":"Spectrochim. Acta A"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.trac.2018.09.013","article-title":"Thioflavin T as a fluorescence probe for biosensing applications","volume":"109","author":"Khusbu","year":"2018","journal-title":"Trends Anal. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"120453","DOI":"10.1016\/j.talanta.2019.120453","article-title":"A turn-on fluorescence assay of alkaline phosphatase activity based on an enzyme-triggered conformational switch of G-quadruplex","volume":"208","author":"Zhou","year":"2020","journal-title":"Talanta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"10864","DOI":"10.1021\/ac502986g","article-title":"Label-free molecular beacons for biomolecular detection","volume":"86","author":"Tan","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"10451","DOI":"10.1021\/acs.analchem.4c01800","article-title":"CRISPR\/Cas12a-powered amplification-free RNA diagnostics by integrating T7 exonuclease-assisted target recycling and split G-quadruplex catalytic signal output","volume":"96","author":"Zhang","year":"2024","journal-title":"Anal. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"16639","DOI":"10.1021\/acs.analchem.4c02723","article-title":"Tetrahedral DNA-based ternary recognition ratiometric fluorescent probes for real-time in situ resolving lysosome subpopulations in living cells via Cl\u2212, Ca2+, and pH","volume":"96","author":"Zou","year":"2024","journal-title":"Anal. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"13443","DOI":"10.1021\/acsanm.3c02029","article-title":"Lipid modification of DNA tetrahedrons enhances cellular uptake, migration, and in vivo uptake","volume":"6","author":"Kansara","year":"2023","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1021\/acsanm.1c03295","article-title":"Co-delivery of chemotherapeutic drugs and immune adjuvants by nanoscale DNA tetrahedrons for synergistic cancer therapy","volume":"5","author":"Wang","year":"2022","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3745","DOI":"10.1021\/acsami.8b20144","article-title":"Electrochemical biosensor for DNA methylation detection through hybridization chain-amplified reaction coupled with a tetrahedral DNA nanostructure","volume":"11","author":"Chen","year":"2019","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"11809","DOI":"10.1021\/acs.analchem.1c02361","article-title":"Electrochemiluminescence biosensor based on entropy-driven amplification and a tetrahedral DNA nanostructure for miRNA-133a detection","volume":"93","author":"Yu","year":"2021","journal-title":"Anal. Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"19121","DOI":"10.1021\/acs.jafc.3c06962","article-title":"Tetrahedral DNA nanostructure-engineered paper-based electrochemical aptasensor for fumonisin B1 detection coupled with Au@Pt nanocrystals as an amplification label","volume":"71","author":"Zhang","year":"2023","journal-title":"J. Agric. Food Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"8804","DOI":"10.1021\/acsanm.2c00787","article-title":"Aptamer-DNA origami-functionalized solid-state nanopores for single-molecule sensing of G-quadruplex formation","volume":"5","author":"Pal","year":"2022","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"121244","DOI":"10.1016\/j.saa.2022.121244","article-title":"Newly found K+-thioflavin T competitive binding to DNA G-quadruplexes and the development of a label-free fluorescent biosensor with extra low detection limit for K+ determination in urine samples","volume":"276","author":"Chitbankluai","year":"2022","journal-title":"Spectrochim. Acta A"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"9285","DOI":"10.1021\/acs.analchem.6b02667","article-title":"Direct fluorescent detection of blood potassium by ion-selective formation of intermolecular G-quadruplex and ligand binding","volume":"88","author":"Yang","year":"2016","journal-title":"Anal. Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"124231","DOI":"10.1016\/j.saa.2024.124231","article-title":"A G-quadruplex\/thioflavin T-based label-free biosensor to detect ClO\u2212 in stress-induced hypertension","volume":"314","author":"Liu","year":"2024","journal-title":"Spectrochim. Acta A"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3761","DOI":"10.2147\/IJN.S403882","article-title":"The current progress of tetrahedral DNA nanostructure for antibacterial application and bone tissue regeneration","volume":"18","author":"Hong","year":"2023","journal-title":"Int. J. Nanomed."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"339566","DOI":"10.1016\/j.aca.2022.339566","article-title":"A signal on-off fluorescence sensor based on the self-assembly DNA tetrahedron for simultaneous detection of ochratoxin A and aflatoxin B1","volume":"1198","author":"Ren","year":"2022","journal-title":"Anal. Chim. Acta"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1021\/ja309588h","article-title":"Thioflavin T as an efficient inducer and selective fluorescent sensor for the human telomeric G-quadruplex DNA","volume":"135","author":"Mohanty","year":"2013","journal-title":"J. Am. Chem. Soc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"27338","DOI":"10.1021\/acsomega.4c01867","article-title":"Development of optical nanosensors for detection of potassium ions and assessment of their biocompatibility with corneal epithelial cells","volume":"9","author":"Dewey","year":"2024","journal-title":"ACS Omega"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1755","DOI":"10.1007\/s10008-023-05392-2","article-title":"Electrochemical sensors based on antimony tin oxide-prussian blue screen-printed electrode and PEDOT-prussian blue for potassium ion detection","volume":"27","author":"Leau","year":"2023","journal-title":"J. Solid State Electrochem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"4558","DOI":"10.1021\/acs.analchem.9b05820","article-title":"NIR remote-controlled \u201clock\u2013unlock\u201d nanosystem for imaging potassium ions in living cells","volume":"92","author":"Cui","year":"2020","journal-title":"Anal. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"10573","DOI":"10.1039\/D4TB01047G","article-title":"A fluorescent ratiometric potassium sensor based on IPG4-silica microparticles for selective detection and fluorescence imaging of potassium cations","volume":"12","author":"Colella","year":"2024","journal-title":"J. Mater. Chem. B"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.ab.2009.12.034","article-title":"An aptamer-based fluorescent biosensor for potassium ion detection using a pyrene-labeled molecular beacon","volume":"400","author":"Shi","year":"2010","journal-title":"Anal. Biochem."}],"container-title":["Biosensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6374\/15\/4\/223\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:06:56Z","timestamp":1760029616000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6374\/15\/4\/223"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,31]]},"references-count":47,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["bios15040223"],"URL":"https:\/\/doi.org\/10.3390\/bios15040223","relation":{},"ISSN":["2079-6374"],"issn-type":[{"value":"2079-6374","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,31]]}}}