{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T10:10:44Z","timestamp":1767348644272,"version":"3.48.0"},"reference-count":48,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biosensors"],"abstract":"<jats:p>This manuscript presents the development of an electrochemical biosensor designed to detect K-562 chronic myeloid leukemia (CML) cells. The biosensor was made of highly oriented pyrolytic graphite (HOPG), functionalized with -OH and -COOH groups by surface etching with strong acids, and subsequently coated with modified titanium dioxide (TiO2-m). TiO2-m is TiO2 modified during its synthesis process using carbon nanotubes functionalized with -OH and -COOH groups. These changes improve the electron transfer kinetics and physicochemical properties of the electrode surface. TiO2-m improves the sensitivity and selectivity towards leukemic cells. The detection process involved three stages: cell culture, cell adhesion onto the TiO2\u2013m electrode, and measurement of the electrochemical signal. Fluorescence microscopy and SEM-EDS confirmed cell adhesion and pseudopod formation on the TiO2-m surface, which is an important finding because K-562 cells are typically nonadherent. Cyclic voltammetry (VC) and differential pulse voltammetry (VDP) demonstrated rapid and sensitive detection of leukemic cells within the concentration range of 6250 to 1,000,000 cells\/mL, achieving high reproducibility and strong linearity (R2 = 98%) with a detection time of 25 s. The VC and VDP demonstrated rapid and sensitive detection of leukemic cells over a concentration range of 6250 to 1,000,000 cells\/mL, achieving adequate reproducibility and stable linearity (R2 = 98%), with a detection time of 25 s. These results indicate that the TiO2-m biosensor is a promising platform for the rapid and efficient electrochemical detection of leukemia cells.<\/jats:p>","DOI":"10.3390\/bios16010028","type":"journal-article","created":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T09:56:23Z","timestamp":1767347783000},"page":"28","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Label-Free Electrochemical Detection of K-562 Leukemia Cells Using TiO2-Modified Graphite Nanostructured Electrode"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3928-4085","authenticated-orcid":false,"given":"Martha Esperanza","family":"Sevilla","sequence":"first","affiliation":[{"name":"Faculty of Systems, Electronics and Industrial Engineering, Technical University of Ambato, Ambato 180101, Ecuador"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0640-0104","authenticated-orcid":false,"given":"Rub\u00e9n Jes\u00fas Camargo","family":"Amado","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering, Universidad del Valle, Cali 76001, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5047-2108","authenticated-orcid":false,"given":"Pablo Ra\u00fal","family":"Valle","sequence":"additional","affiliation":[{"name":"Faculty of Civil and Mechanical Engineering, Technical University of Ambato, Ambato 180101, Ecuador"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1081","DOI":"10.1200\/JCO.19.03141","article-title":"Clinical Cancer Advances 2020: Annual Report on Progress Against Cancer From the American Society of Clinical Oncology","volume":"38","author":"Markham","year":"2020","journal-title":"J. Clin. Oncol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"100723","DOI":"10.1016\/j.jbior.2020.100723","article-title":"Cancer genomics of lung cancer including malignant mesothelioma: A brief overview of current status and future prospects","volume":"78","author":"Jhanwar","year":"2020","journal-title":"Adv. Biol. Regul."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Daci, M., Berisha, L., Mercatante, D., Rodriguez-Estrada, M.T., Jin, Z., Huang, Y., and Amorati, R. (2024). Advancements in Biosensors for Lipid Peroxidation and Antioxidant Protection in Food: A Critical Review. Antioxidants, 13.","DOI":"10.3390\/antiox13121484"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"155161","DOI":"10.1016\/j.prp.2024.155161","article-title":"The impact of the BCR-ABL oncogene in the pathology and treatment of chronic myeloid leukemia","volume":"254","author":"Nsairat","year":"2024","journal-title":"Pathol.\u2014Res. Pr."},{"key":"ref_5","unstructured":"A. Bahar, N.A.-H. (2025). Molecular Cytogenetic Study on BCR\/ABL Fusion Gene in Chronic Myeloid Leukemia Patients. [Ph.D. Thesis, University of Anbar]."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"101730","DOI":"10.1016\/j.ejon.2020.101730","article-title":"Experiences of living with chronic myeloid leukaemia and adhering to tyrosine kinase inhibitors: A thematic synthesis of qualitative studies","volume":"45","author":"Hewison","year":"2020","journal-title":"Eur. J. Oncol. Nurs."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"100569","DOI":"10.1016\/j.sbsr.2023.100569","article-title":"Nanosensors and their applications in early diagnosis of cancer","volume":"41","author":"Khazaei","year":"2023","journal-title":"Sens. Bio-Sensing Res."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Allegra, A., Petrarca, C., Di Gioacchino, M., Mirabile, G., and Gangemi, S. (2022). Electrochemical Biosensors in the Diagnosis of Acute and Chronic Leukemias. Cancers, 15.","DOI":"10.3390\/cancers15010146"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"037554","DOI":"10.1149\/1945-7111\/ab67aa","article-title":"Review\u2014Nanostructured Materials-Based Nanosensors","volume":"167","author":"Reda","year":"2020","journal-title":"J. Electrochem. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"100375","DOI":"10.1016\/j.snr.2025.100375","article-title":"Molecularly imprinted poly(o-aminophenol)-based electrochemical sensor for the quantitative detection of a VP28 biomarker for white spot syndrome virus","volume":"10","author":"Yun","year":"2025","journal-title":"Sens. Actuators Rep."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"136466","DOI":"10.1016\/j.snb.2024.136466","article-title":"Cascade signal amplifying strategy for ultrasensitive detection of tumor biomarker by DNAzyme cleaving mediated HCR","volume":"420","author":"Chen","year":"2024","journal-title":"Sens. Actuators B Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"020025","DOI":"10.1063\/5.0025760","article-title":"Sensitive biosensor for chronic myeloid leukemia detection using multi-wall carbon nanotube","volume":"2276","author":"Gulati","year":"2020","journal-title":"AIP Conf. Proc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"121","DOI":"10.2217\/nnm.13.191","article-title":"Shaping cancer nanomedicine: The effect of particle shape on the in vivo journey of nanoparticle","volume":"9","author":"Toy","year":"2014","journal-title":"Nanomedicine"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"100626","DOI":"10.1016\/j.cscee.2024.100626","article-title":"Nano titanium oxide (nano-TiO2): A review of synthesis methods, properties, and applications","volume":"9","author":"Hsu","year":"2024","journal-title":"Case Stud. Chem. Environ. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"15381","DOI":"10.1007\/s10854-020-04102-2","article-title":"Sonochemical synthesis of magnetic Fe3O4\/graphene nanocomposites for label-free electrochemical biosensors","volume":"31","author":"Suhanto","year":"2020","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1121","DOI":"10.1016\/j.elecom.2008.05.030","article-title":"Detection and distinguishability of leukemia cancer cells based on Au nanoparticles modified electrodes","volume":"10","author":"Hu","year":"2008","journal-title":"Electrochem. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4340","DOI":"10.1016\/j.arabjc.2016.04.019","article-title":"Synthesis, characterization, and functionalization of ZnO nanoparticles by N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (TMSEDTA): Investigation of the interactions between Phloroglucinol and ZnO@TMSEDTA","volume":"12","author":"Barrak","year":"2019","journal-title":"Arab. J. Chem."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Li, H., Li, D., Chen, H., Yue, X., Fan, K., Dong, L., and Wang, G. (2023). Application of Silicon Nanowire Field Effect Transistor (SiNW-FET) Biosensor with High Sensitivity. Sensors, 23.","DOI":"10.3390\/s23156808"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"100170","DOI":"10.1016\/j.nxnano.2025.100170","article-title":"Nanomaterials-based Field Effect Transistor biosensor for cancer therapy","volume":"8","author":"Sasikumar","year":"2025","journal-title":"Next Nanotechnol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/j.bios.2018.04.053","article-title":"Versatile graphene biosensors for enhancing human cell therapy","volume":"117","author":"Tite","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"646","DOI":"10.1186\/1556-276X-7-646","article-title":"Preparation of hollow TiO2 nanoparticles through TiO2 deposition on polystyrene latex particles and characterizations of their structure and photocatalytic activity","volume":"7","author":"Wang","year":"2012","journal-title":"Nanoscale Res. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.carbpol.2018.06.033","article-title":"Effect of isolation methods of chitin nanocrystals on the properties of chitin-silver hybrid nanoparticles","volume":"197","author":"Oun","year":"2018","journal-title":"Carbohydr. Polym."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1007\/s13762-018-1857-x","article-title":"Effect on different TiO2 photocatalyst supports on photodecolorization of synthetic dyes: A review","volume":"16","author":"Adnan","year":"2018","journal-title":"Int. J. Environ. Sci. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.apmt.2018.11.005","article-title":"One-dimensional anodic TiO2 nanotubes coated by atomic layer deposition: Towards advanced applications","volume":"14","author":"Dvorak","year":"2019","journal-title":"Appl. Mater. Today"},{"key":"ref_25","unstructured":"(2025, December 01). WO2016055869\u2014Synthesis of Nanocompounds Comprising Anatase-Phase Titanium Oxide And Compositions Containing Same For The Treatment Of Cancer. Available online: https:\/\/patentscope2.wipo.int\/search\/en\/detail.jsf?docId=WO2016055869."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1016\/j.msec.2017.05.137","article-title":"Nonenzymatic glucose sensor based on Ag&Pt hollow nanoparticles supported on TiO2 nanotubes","volume":"80","author":"Wang","year":"2017","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_27","first-page":"e21110838","article-title":"M\u00e9todo de funcionalizaci\u00f3n qu\u00edmica para la obtenci\u00f3n de \u00f3xido de grafeno adherido a la superficie de placas de grafito pirol\u00edtica de alta densidad por spray coating \u00e1cido","volume":"23","author":"Amado","year":"2021","journal-title":"Ing. Y Compet."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.bios.2012.05.033","article-title":"A glucose biosensor based on TiO2\u2013Graphene composite","volume":"38","author":"Jang","year":"2012","journal-title":"Biosens. Bioelectron."},{"key":"ref_29","unstructured":"(2025, December 01). US20170281770\u2014Synthesis of Nanocompounds Comprising Anatase-phase Titanium Oxide and Compositions Containing Same for the Treatment of Cancer. Available online: https:\/\/patentscope2.wipo.int\/search\/en\/detail.jsf?docId=US204579236&_fid=WO2016055869."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"8778","DOI":"10.1039\/C8RA09577A","article-title":"A review on graphene-based nanocomposites for electrochemical and fluorescent biosensors","volume":"9","author":"Krishnan","year":"2019","journal-title":"RSC Adv."},{"key":"ref_31","first-page":"81","article-title":"Scanning electron microscopic study of the adhesion of a human megakaryocytic leukemia cell line (CMK11-5)","volume":"26","author":"Nagano","year":"1993","journal-title":"Med Mol. Morphol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"11680","DOI":"10.1021\/ac502969x","article-title":"Chronic Myeloid Leukemia Drug Evaluation Using a Multisignal Ampli fi ed Photoelectrochemical Sensing Platform","volume":"86","author":"Zhou","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1016\/j.elecom.2006.11.040","article-title":"A disposable impedance sensor for electrochemical study and monitoring of adhesion and proliferation of K562 leukaemia cells","volume":"9","author":"Ding","year":"2007","journal-title":"Electrochem. Commun."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1016\/j.bios.2016.11.006","article-title":"Biosensing breast cancer cells based on a three-dimensional TIO2 nanomembrane transducer","volume":"92","author":"Zanghelini","year":"2017","journal-title":"Biosens. Bioelectron."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.bios.2013.09.044","article-title":"A new disposable electrode for electrochemical study of leukemia K562 cells and anticancer drug sensitivity test","volume":"53","author":"Yu","year":"2014","journal-title":"Biosens. Bioelectron."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.aca.2015.06.050","article-title":"Coupling a universal DNA circuit with graphene sheets\/polyaniline\/AuNPs nanocomposites for the detection of BCR\/ABL fusion gene","volume":"889","author":"Chen","year":"2015","journal-title":"Anal. Chim. Acta"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Bola\u00f1os, K.L., Nagles, E., Arancibia, V., Otiniano, M., Leiva, Y., Mari\u00f1o, A., and Scarpetta, L. (2014). Optimizing adsorption voltammetric technique (AdSV) in determining of amaranth on carbon printed electrodes. Eff. Surfactants Sensit., 80.","DOI":"10.37761\/rsqp.v80i2.156"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Garcia Diosa, J.A., Gonzalez Orive, A., Grundmeier, G., Camargo Amado, R.J., and Keller, A. (2021). Morphological Dynamics of Leukemia Cells on TiO 2 Nanoparticle Coatings Studied by AFM. Appl. Sci., 11.","DOI":"10.3390\/app11219898"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"12966","DOI":"10.1039\/D3RA01160G","article-title":"Ultrasensitive electrochemical biosensor for detection of circulating tumor cells based on a highly efficient enzymatic cascade reaction","volume":"13","author":"Dong","year":"2023","journal-title":"RSC Adv."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Fang, B., Chen, Y., Jiang, H., Liu, X., and Wang, X. (2025). Nanomaterial Engineered Biosensors and Stimulus\u2013Responsive Platform for Emergency Monitoring and Intelligent Diagnosis. Biosensors, 15.","DOI":"10.3390\/bios15120789"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.bios.2012.10.057","article-title":"Graphene oxide\/poly-l-lysine assembled layer for adhesion and electrochemical impedance detection of leukemia K562 cancercells","volume":"42","author":"Zhang","year":"2013","journal-title":"Biosens. Bioelectron."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"325501","DOI":"10.1088\/0957-4484\/26\/32\/325501","article-title":"Paper-based cell impedance sensor and its application for cytotoxic evaluation","volume":"26","author":"Yu","year":"2015","journal-title":"Nanotechnology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"18001","DOI":"10.1002\/chem.201604354","article-title":"Enhanced Peroxidase-Like Properties of Graphene\u2013Hemin-Composite Decorated with Au Nanoflowers as Electrochemical Aptamer Biosensor for the Detection of K562 Leukemia Cancer Cells","volume":"22","author":"Liu","year":"2016","journal-title":"Chem.\u2014A Eur. J."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.ab.2018.07.020","article-title":"Single-wall carbon nanotube based electrochemical immunoassay for leukemia detection","volume":"557","author":"Gulati","year":"2018","journal-title":"Anal. Biochem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.snb.2018.05.019","article-title":"Leukemia biomarker detection by using photoconductive response of CNT electrode: Analysis of sensing mechanism based on charge transfer induced Fermi level fluctuation","volume":"270","author":"Gulati","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.talanta.2015.05.008","article-title":"Electrochemical K-562 cells sensor based on origami paper device for point-of-care testing","volume":"145","author":"Ge","year":"2015","journal-title":"Talanta"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3371","DOI":"10.1016\/j.bios.2010.12.030","article-title":"Electrochemical cell-based chip for the detection of toxic effects of bisphenol-A on neuroblastoma cells","volume":"26","author":"Kafi","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"4503","DOI":"10.1038\/s41598-019-41171-8","article-title":"Evaluation of a new lymphocyte proliferation assay based on cyclic voltammetry; an alternative method","volume":"9","author":"Nikbakht","year":"2019","journal-title":"Sci. Rep."}],"container-title":["Biosensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6374\/16\/1\/28\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T10:09:09Z","timestamp":1767348549000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6374\/16\/1\/28"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,1]]},"references-count":48,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["bios16010028"],"URL":"https:\/\/doi.org\/10.3390\/bios16010028","relation":{},"ISSN":["2079-6374"],"issn-type":[{"value":"2079-6374","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,1]]}}}