{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T22:53:14Z","timestamp":1783551194425,"version":"3.55.0"},"reference-count":43,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,4,11]],"date-time":"2023-04-11T00:00:00Z","timestamp":1681171200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Liao Ning Science and Technology Development Foundation Guided by Central Government","award":["2022JH6\/100100024"],"award-info":[{"award-number":["2022JH6\/100100024"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Monitoring of uric acid (UA) levels in biological samples is of great significance for human health, while the development of a simple and effective method for the precise determination of UA content is still challenging. In the present study, a two-dimensional (2D) imine-linked crystalline pyridine-based covalent organic framework (TpBpy COF) was synthesized using 2,4,6-triformylphloroglucinol (Tp) and [2,2\u2032-bipyridine]-5,5\u2032-diamine (Bpy) as precursors via Schiff-base condensation reactions and was characterized with scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), Powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy, and Brunauer\u2013Emmett\u2013Teller (BET) assays. The as-synthesized TpBpy COF exhibited excellent visible light-induced oxidase-like activity, ascribed to the generation of superoxide radicals (O2\u2022\u2212) by photo-generated electron transfer. TpBpy COF could efficiently oxidase the colorless substrate 3,3\u2032,5,5\u2032-tetramethylbenzydine (TMB) into blue oxidized TMB (oxTMB) under visible light irradiation. Based on the color fade of the TpBpy COF + TMB system by UA, a colorimetric procedure was developed for UA determination with a detection limit of 1.7 \u03bcmol L\u22121. Moreover, a smartphone-based sensing platform was also constructed for instrument-free and on-site detection of UA with a sensitive detection limit of 3.1 \u03bcmol L\u22121. The developed sensing system was adopted for UA determination in human urine and serum samples with satisfactory recoveries (96.6\u2013107.8%), suggesting the potential practical application of the TpBpy COF-based sensor for UA detection in biological samples.<\/jats:p>","DOI":"10.3390\/s23083881","type":"journal-article","created":{"date-parts":[[2023,4,12]],"date-time":"2023-04-12T02:08:11Z","timestamp":1681265291000},"page":"3881","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Design of Smartphone-Assisted Point-of-Care Platform for Colorimetric Sensing of Uric Acid via Visible Light-Induced Oxidase-Like Activity of Covalent Organic Framework"],"prefix":"10.3390","volume":"23","author":[{"given":"Qi","family":"Kang","sequence":"first","affiliation":[{"name":"College of Sciences, Northeastern University, Shenyang 110819, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yulong","family":"Xu","sequence":"additional","affiliation":[{"name":"College of Sciences, Northeastern University, Shenyang 110819, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7189-5022","authenticated-orcid":false,"given":"Xuwei","family":"Chen","sequence":"additional","affiliation":[{"name":"College of Sciences, Northeastern University, Shenyang 110819, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1627","DOI":"10.1016\/j.bios.2003.12.026","article-title":"Detection of serum uric acid using the optical polymeric enzyme biochip system","volume":"19","author":"Huang","year":"2004","journal-title":"Biosens. Bioelectron."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"111420","DOI":"10.1016\/j.bios.2019.111420","article-title":"Fabrication of an efficient and sensitive colorimetric biosensor based on Uricase\/Th-MOF for uric acid sensing in biological samples","volume":"141","author":"Sohrabi","year":"2019","journal-title":"Biosens. Bioelectron."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1007\/s11426-020-9923-9","article-title":"Bio-inspired nanoenzyme for metabolic reprogramming and anti-inflammatory treatment of hyperuricemia and gout","volume":"64","author":"Zhang","year":"2021","journal-title":"Sci. China Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1722","DOI":"10.1038\/sj.ki.5000391","article-title":"Unearthing uric acid: An ancient factor with recently found significance in renal and cardiovascular disease","volume":"69","author":"Nakagawa","year":"2006","journal-title":"Kidney Int."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.cccn.2004.09.024","article-title":"Uric acid: An abettor or protector in calcium oxalate urolithiasis? Biochemical study in stone formers","volume":"353","author":"Srinivasan","year":"2005","journal-title":"Clin. Chim. Acta"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"E25","DOI":"10.1212\/01.wnl.0000184611.55051.f3","article-title":"Self-mutilation in the Lesch-Nyhan syndrome","volume":"65","author":"Maramattom","year":"2005","journal-title":"Neurology"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.jchromb.2015.06.021","article-title":"Validation of a multi-analyte HPLC-DAD method for determination of uric acid, creatinine, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid and 2-methylhippuric acid in human urine","volume":"998","author":"Remane","year":"2015","journal-title":"J. Chromatogr. B"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1007\/s00604-017-2614-4","article-title":"Uricase based fluorometric determination of uric acid based on the use of graphene quantum dot@silver core-shell nanocomposites","volume":"185","author":"Kong","year":"2018","journal-title":"Microchim. Acta"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1016\/j.bios.2017.08.028","article-title":"Development of luminol-N-hydroxyphthalimide chemiluminescence system for highly selective and sensitive detection of superoxide dismutase, uric acid and Co2+","volume":"99","author":"Saqib","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2088","DOI":"10.1039\/c1ay05065f","article-title":"Simple method for simultaneous detection of uric acid, xanthine and hypoxanthine in fish samples using a glassy carbon electrode modified with as commercially received multiwalled carbon nanotubes","volume":"3","author":"Kumar","year":"2011","journal-title":"Anal. Methods"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.cca.2014.04.033","article-title":"Evaluation of an electrochemical biosensor for uric acid measurement in human whole blood samples","volume":"436","author":"Liao","year":"2014","journal-title":"Clin. Chim. Acta"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.snb.2016.12.127","article-title":"A highly selective and sensitive colorimetric uric acid biosensor based on Cu(II)-catalyzed oxidation of 3,3\u2032,5,5\u2032-tetramethylbenzidine","volume":"244","author":"Lu","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"5152","DOI":"10.1021\/acs.analchem.9b05645","article-title":"Doping nitrogen into Q-graphene by plasma treatment toward peroxidase mimics with enhanced catalysis","volume":"92","author":"Li","year":"2020","journal-title":"Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.biomaterials.2019.04.007","article-title":"A series of MOF\/Ce-based nanozymes with dual enzyme-like activity disrupting biofilms and hindering recolonization of bacteria","volume":"208","author":"Liu","year":"2019","journal-title":"Biomaterials"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"10292","DOI":"10.1039\/C7NR03399K","article-title":"Chitosan-stabilized platinum nanoparticles as effective oxidase mimics for colorimetric detection of acid phosphatase","volume":"9","author":"Deng","year":"2017","journal-title":"Nanoscale"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1016\/j.biomaterials.2010.09.040","article-title":"Au@Pt nanostructures as oxidase and peroxidase mimetics for use in immunoassays","volume":"32","author":"He","year":"2011","journal-title":"Biomaterials"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"83738","DOI":"10.1039\/C6RA11483K","article-title":"Enzyme mimicking inorganic hybrid Ni@MnO2 for colorimetric detection of uric acid in serum samples","volume":"6","author":"Pal","year":"2016","journal-title":"RSC Adv."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"649","DOI":"10.1007\/s00216-022-04453-1","article-title":"Platinum nanoparticles confined in metal-organic frameworks as excellent peroxidase-like nanozymes for detection of uric acid","volume":"415","author":"Xia","year":"2022","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1007\/s00604-019-3759-0","article-title":"A nanocomposite prepared from silver nanoparticles and carbon dots with peroxidase mimicking activity for colorimetric and SERS-based determination of uric acid","volume":"186","author":"Wang","year":"2019","journal-title":"Microchim. Acta"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"548","DOI":"10.1039\/C2CS35072F","article-title":"Covalent organic frameworks (COFs): From design to applications","volume":"42","author":"Ding","year":"2013","journal-title":"Chem. Soc. Rev."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"8316","DOI":"10.1039\/C9SC02601K","article-title":"Donor-acceptor covalent organic frameworks for visible light induced free radical polymerization","volume":"10","author":"Pachfule","year":"2019","journal-title":"Chem. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"21750","DOI":"10.1021\/acsami.2c04391","article-title":"Construction of donor-acceptor heteroporous covalent organic frameworks as photoregulated oxidase-like nanozymes for sensing signal amplification","volume":"14","author":"Li","year":"2022","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Xu, Y., Wei, J., and Chen, X. (2022). Light-responsive sulfone-based covalent organic framework as metal-free nanoenzyme for visual colorimetric determination of uranium. Chemosensors, 10.","DOI":"10.3390\/chemosensors10070248"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"108119","DOI":"10.1016\/j.nanoen.2022.108119","article-title":"NIR light-induced rapid self-healing hydrogel toward multifunctional applications in sensing","volume":"107","author":"Xu","year":"2023","journal-title":"Nano Energy"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"107955","DOI":"10.1016\/j.nanoen.2022.107955","article-title":"Highly sensitive strain sensor and self-powered triboelectric nanogenerator using a fully physical crosslinked double-network conductive hydrogel","volume":"104","author":"Luo","year":"2023","journal-title":"Nano Energy"},{"key":"ref_26","first-page":"123195","article-title":"Fully physical crosslinked BSA-based conductive hydrogels with high strength and fast self-recovery for human motion and wireless electrocardiogram sensing","volume":"230","author":"Xu","year":"2023","journal-title":"Nano Energy"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.aca.2018.02.073","article-title":"Uricase-free on-demand colorimetric biosensing of uric acid enabled by integrated CoP nanosheet arrays as a monolithic peroxidase mimic","volume":"1021","author":"He","year":"2018","journal-title":"Anal. Chim. Acta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4558","DOI":"10.1039\/D1NJ06222K","article-title":"Low-temperature and gram-scale synthesis of chemically stable covalent organic frameworks in an aqueous medium","volume":"46","author":"Ma","year":"2022","journal-title":"New J. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2682","DOI":"10.1039\/C5TA10521H","article-title":"A mechanochemically synthesized covalent organic framework as a proton-conducting solid electrolyte","volume":"4","author":"Shinde","year":"2016","journal-title":"J. Mater. Chem. A"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1932","DOI":"10.1002\/anie.201913983","article-title":"Developing luminescent ratiometric thermometers based on a covalent organic framework (COF)","volume":"59","author":"Kaczmarek","year":"2020","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3105","DOI":"10.1002\/chem.201805550","article-title":"Bimetallic covalent organic frameworks for constructing multifunctional Electrocatalyst","volume":"25","author":"Wu","year":"2019","journal-title":"Chem. Eur. J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"7245","DOI":"10.1021\/jacs.2c00285","article-title":"Chiral-induced ultrathin covalent organic frameworks nanosheets with tunable circularly polarized luminescence","volume":"144","author":"Chen","year":"2022","journal-title":"J. Am. Chem. Soc."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2169","DOI":"10.1007\/s11426-021-1088-2","article-title":"Covalent-organic frameworks with keto-enol tautomerism for efficient photocatalytic oxidative coupling of amines to imines under visible light","volume":"64","author":"Wu","year":"2021","journal-title":"Sci. China Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"E1825","DOI":"10.1016\/S1872-2040(17)61083-1","article-title":"Ultra-small CuS nanoparticles as peroxidase mimetics for sensitive and colorimetric detection of uric acid in human serum","volume":"46","author":"Wang","year":"2018","journal-title":"Chin. J. Anal. Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/j.snb.2017.03.145","article-title":"Metal-organic framework coated Fe3O4 magnetic nanoparticles with peroxidase-like activity for colorimetric sensing of cholesterol","volume":"249","author":"Wu","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_36","first-page":"12251","article-title":"One-step electrochemical synthesis of ultrathin graphitic carbon nitride nanosheets and their application to the detection of uric acid","volume":"51","author":"Lu","year":"2015","journal-title":"ChemComm"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"9123","DOI":"10.1021\/acsomega.9b04071","article-title":"Peroxidase-like behavior of Ni thin films deposited by glancing angle deposition for enzyme-free uric acid sensing","volume":"5","author":"Tripathi","year":"2020","journal-title":"ACS Omega"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1016\/j.bios.2016.07.055","article-title":"Upconversion ratiometric fluorescence and colorimetric dual-readout assay for uric acid","volume":"86","author":"Fang","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.talanta.2018.08.015","article-title":"A novel ratiometric fluorescent probe for the detection of uric acid in human blood based on H2O2-mediated fluorescence quenching of gold\/silver nanoclusters","volume":"191","author":"Wang","year":"2018","journal-title":"Talanta"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/S0003-2670(02)01484-8","article-title":"Microdialysis sampling and monitoring of uric acid in vivo by a chemiluminescence reaction and an enzyme on immobilized chitosan support membrane","volume":"478","author":"Yao","year":"2003","journal-title":"Anal. Chim. Acta"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2437","DOI":"10.1016\/j.snb.2017.09.036","article-title":"Photochemical one-pot synthesis of reduced graphene oxide\/prussian blue nanocomposite for simultaneous electrochemical detection of ascorbic acid, dopamine, and uric acid","volume":"255","author":"Katic","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_42","unstructured":"International Telecommunication Union (2023, March 31). Studio Encoding Parameters of Digital Television for Standard 4:3 and Wide-Screen 16:9 Aspect Ratios. Available online: https:\/\/www.itu.int\/pub\/R-REC\/en."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"14419","DOI":"10.1021\/acs.analchem.2c03179","article-title":"Fluorescence\/colorimetry\/smartphone triple-mode sensing of dopamine by a cof-based peroxidase-mimic platform","volume":"94","author":"Yue","year":"2022","journal-title":"Anal. Chem."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/8\/3881\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:13:49Z","timestamp":1760123629000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/8\/3881"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,4,11]]},"references-count":43,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2023,4]]}},"alternative-id":["s23083881"],"URL":"https:\/\/doi.org\/10.3390\/s23083881","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,4,11]]}}}