{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T02:53:26Z","timestamp":1778813606673,"version":"3.51.4"},"reference-count":43,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2018,3,15]],"date-time":"2018-03-15T00:00:00Z","timestamp":1521072000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This work reports an amperometric biosensor for the determination of miRNA-21, a relevant oncogene. The methodology involves a competitive DNA-target miRNA hybridization assay performed on the surface of magnetic microbeads (MBs) and amperometric transduction at screen-printed carbon electrodes (SPCEs). The target miRNA competes with a synthetic fluorescein isothiocyanate (FITC)-modified miRNA with an identical sequence for hybridization with a biotinylated and complementary DNA probe (b-Cp) immobilized on the surface of streptavidin-modified MBs (b-Cp-MBs). Upon labeling, the FITC-modified miRNA attached to the MBs with horseradish peroxidase (HRP)-conjugated anti-FITC Fab fragments and magnetic capturing of the MBs onto the working electrode surface of SPCEs. The cathodic current measured at \u22120.20 V (versus the Ag pseudo-reference electrode) was demonstrated to be inversely proportional to the concentration of the target miRNA. This convenient biosensing method provided a linear range between 0.7 and 10.0 nM and a limit of detection (LOD) of 0.2 nM (5 fmol in 25 \u03bcL of sample) for the synthetic target miRNA without any amplification step. An acceptable selectivity towards single-base mismatched oligonucleotides, a high storage stability of the b-Cp-MBs, and usefulness for the accurate determination of miRNA-21 in raw total RNA (RNAt) extracted from breast cancer cells (MCF-7) were demonstrated.<\/jats:p>","DOI":"10.3390\/s18030863","type":"journal-article","created":{"date-parts":[[2018,3,15]],"date-time":"2018-03-15T05:11:28Z","timestamp":1521090688000},"page":"863","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":37,"title":["Single-Step Incubation Determination of miRNAs in Cancer Cells Using an Amperometric Biosensor Based on Competitive Hybridization onto Magnetic Beads"],"prefix":"10.3390","volume":"18","author":[{"given":"Eva","family":"Vargas","sequence":"first","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eloy","family":"Povedano","sequence":"additional","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"V\u00edctor","family":"Montiel","sequence":"additional","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rebeca","family":"Torrente-Rodr\u00edguez","sequence":"additional","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mohamed","family":"Zouari","sequence":"additional","affiliation":[{"name":"Sensors and Biosensors Group, Laboratory of Analytical Chemistry and Electrochemistry (LR99ES15), Department of Chemistry, Faculty of Science, University of Tunis El Manar, Rue B\u00e9chir Salem Belkheria, Tunis El-Manar, 2092 Tunis, Tunisia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0427-6322","authenticated-orcid":false,"given":"Juan","family":"Montoya","sequence":"additional","affiliation":[{"name":"Cannan Research and Investment &amp; Faculty of Medicine, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8938-8221","authenticated-orcid":false,"given":"Noureddine","family":"Raouafi","sequence":"additional","affiliation":[{"name":"Sensors and Biosensors Group, Laboratory of Analytical Chemistry and Electrochemistry (LR99ES15), Department of Chemistry, Faculty of Science, University of Tunis El Manar, Rue B\u00e9chir Salem Belkheria, Tunis El-Manar, 2092 Tunis, Tunisia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9928-6613","authenticated-orcid":false,"given":"Susana","family":"Campuzano","sequence":"additional","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2271-1383","authenticated-orcid":false,"given":"Jos\u00e9","family":"Pingarr\u00f3n","sequence":"additional","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,3,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e3045","DOI":"10.1038\/cddis.2017.440","article-title":"Circulating microRNAs in breast cancer: Novel diagnostic and prognostic biomarkers","volume":"8","author":"Hamam","year":"2017","journal-title":"Cell Death Dis."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Campuzano, S., Pedrero, M., and Pingarr\u00f3n, J.M. (2017). Non-Invasive Breast Cancer Diagnosis through Electrochemical Biosensing at Different Molecular Levels. Sensors, 17.","DOI":"10.3390\/s17091993"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Nicolini, A., Ferrari, P., and Duffy, M.J. (2017). Prognostic and predictive biomarkers in breast cancer: Past, present and future. Semin. Cancer Biol.","DOI":"10.1016\/j.semcancer.2017.08.010"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1016\/j.bios.2017.08.036","article-title":"Recent advances in signal amplification strategy based on oligonucleotide and nanomaterials for microRNA detection-a review","volume":"99","author":"Chen","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"116","DOI":"10.7150\/jca.2.116","article-title":"miRNA Biomarkers in Breast Cancer Detection and Management","volume":"2","author":"Fu","year":"2011","journal-title":"J. Cancer"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.trac.2017.04.006","article-title":"Early stage screening of breast cancer using electrochemical biomarker detection","volume":"91","author":"Hasanzadeh","year":"2017","journal-title":"Trends Anal. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2319","DOI":"10.1021\/ac702577a","article-title":"Bioluminescence-Based Detection of MicroRNA, miR21 in Breast Cancer Cells","volume":"80","author":"Cissell","year":"2008","journal-title":"Anal. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"10110","DOI":"10.1021\/ac102131s","article-title":"Surface plasmon resonance biosensor for rapid label-free detection of microribonucleic acid at subfemtomole level","volume":"82","author":"Zhang","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"11368","DOI":"10.1021\/acs.analchem.5b02790","article-title":"Label-free and enzyme-free homogeneous electrochemical biosensing strategy based on hybridization chain reaction: A facile, sensitive, and highly specific microRNA assay","volume":"87","author":"Liu","year":"2015","journal-title":"Anal. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3543","DOI":"10.1021\/acs.biomac.5b00959","article-title":"Ultrasensitive detection of microRNA in tumor cells and tissues via continuous assembly of DNA probe","volume":"16","author":"Liao","year":"2015","journal-title":"Biomacromolecules"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"452","DOI":"10.1016\/j.bios.2015.09.006","article-title":"An immobilization-free electrochemical impedance biosensor based on duplex-specific nuclease assisted target recycling for amplified detection of microRNA","volume":"75","author":"Zhang","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1016\/j.bios.2017.08.007","article-title":"MicroRNA biosensors: Opportunities and challenges among conventional and commercially available techniques","volume":"99","author":"Kilic","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1038\/nmeth717","article-title":"Microarray-based, high-throughput gene expression profiling of microRNAs","volume":"1","author":"Nelson","year":"2004","journal-title":"Nat. Methods"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e17","DOI":"10.1093\/nar\/gni019","article-title":"An oligonucleotide microarray for microRNA expression analysis based on labeling RNA with quantum dot and nanogold probe","volume":"33","author":"Liang","year":"2005","journal-title":"Nucleic Acids Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1261\/rna.1947110","article-title":"Systematic comparison of microarray profiling, real-time PCR, and next-generation sequencing technologies for measuring differential microRNA expression","volume":"16","author":"Git","year":"2010","journal-title":"RNA"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3497","DOI":"10.1007\/s00216-017-0298-6","article-title":"Amplification-free detection of microRNAs via a rapid microarray-based sandwich assay","volume":"409","author":"Clancy","year":"2017","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e175","DOI":"10.1093\/nar\/gnh171","article-title":"Sensitive and specific detection of microRNAs by northern blot analysis using LNA-modified oligonucleotide probes","volume":"32","author":"Hornyik","year":"2004","journal-title":"Nucleic Acids Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"e60","DOI":"10.1093\/nar\/gkm112","article-title":"Carbodiimide-mediated cross-linking of RNA to nylon membranes improves the detection of siRNA, miRNA and piRNA by northern blot","volume":"35","author":"Pall","year":"2007","journal-title":"Nucleic Acids Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5446","DOI":"10.1021\/ac900598d","article-title":"Real-time polymerase chain reaction microRNA detection based on enzymatic stem-loop probes ligation","volume":"81","author":"Li","year":"2009","journal-title":"Anal. Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1016\/j.ymeth.2010.01.032","article-title":"Analysis of circulating microRNA biomarkers in plasma and serum using quantitative reverse transcription-PCR (qRT-PCR)","volume":"50","author":"Kroh","year":"2010","journal-title":"Methods"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e179","DOI":"10.1093\/nar\/gni178","article-title":"Real-time quantification of microRNAs by stem-loop RT-PCR","volume":"33","author":"Chen","year":"2005","journal-title":"Nucleic Acids Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.aca.2005.01.073","article-title":"A disposable immunomagnetic electrochemical sensor based on functionalized magnetic beads and carbon-based screen-printed electrodes (SPCEs) for the detection of polychlorinated biphenyls (PCBs)","volume":"538","author":"Centi","year":"2005","journal-title":"Anal. Chim. Acta"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2184","DOI":"10.1016\/j.bios.2006.10.014","article-title":"Electrochemical magneto immunosensing of antibiotic residues in milk","volume":"22","author":"Zacco","year":"2007","journal-title":"Biosens. Bioelectron."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.aca.2007.10.046","article-title":"A review on novel developments and applications of immunosensors in food analysis","volume":"605","author":"Ricci","year":"2007","journal-title":"Anal. Chim. Acta"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.electacta.2012.03.147","article-title":"Electrochemical biosensors based on magnetic micro\/nano particles","volume":"84","author":"Xu","year":"2012","journal-title":"Electrochim. Acta"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"6168","DOI":"10.1002\/anie.201403270","article-title":"Magnetobiosensors based on viral protein p19 for microRNA determination in cancer cells and tissues","volume":"53","author":"Campuzano","year":"2014","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2080","DOI":"10.1002\/elan.201400317","article-title":"Direct determination of miR-21 in total RNA extracted from breast cancer samples using magnetosensing platforms and the p19 viral protein as detector bioreceptor","volume":"26","author":"Campuzano","year":"2014","journal-title":"Electroanalysis"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.elecom.2015.09.012","article-title":"An electrochemical microRNA biosensor based on protein p19 combining an acridone derivate as indicator and DNA concatamers for signal amplification","volume":"60","author":"Li","year":"2015","journal-title":"Electrochem. Commun."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1021\/acssensors.6b00266","article-title":"Fast electrochemical miRNAs determination in cancer cells and tumor tissues with antibody-functionalized magnetic microcarriers","volume":"1","author":"Campuzano","year":"2016","journal-title":"ACS Sens."},{"key":"ref_30","first-page":"1064","article-title":"Electrochemical miRNAs Determination in Formalin-Fixed, Paraffin-Embedded Breast Tumor Tissues Association with HER2 Expression","volume":"3","author":"Campuzano","year":"2016","journal-title":"JSM Biotechnol. Bioeng."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Vargas, E., Torrente-Rodr\u00edguez, R.M., Ruiz-Valdepe\u00f1as Montiel, V., Povedano, E., Pedrero, M., Montoya, J.J., Campuzano, S., and Pingarr\u00f3n, J.M. (2017). Magnetic Beads-Based Sensor with tailored sensitivity for rapid and single-step amperometric determination of miRNAs. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18112151"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"516","DOI":"10.1016\/j.bios.2016.07.003","article-title":"Sensitive electrochemical determination of miRNAs based on a sandwich assay onto magnetic microcarriers and hybridization chain reaction amplification","volume":"86","author":"Campuzano","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1093\/ajh\/hpx197","article-title":"Noncoding RNAs in Cardiovascular Disease: Pathological Relevance and Emerging Role as Biomarkers and Therapeutics","volume":"31","author":"Gangwar","year":"2018","journal-title":"Am. J. Hypertens."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2235","DOI":"10.1002\/elan.201200503","article-title":"Amperometric Magnetoimmunosensors for Direct Determination of D-Dimer in Human Serum","volume":"24","author":"Gamella","year":"2012","journal-title":"Electroanalysis"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"10822","DOI":"10.1021\/acs.analchem.5b01930","article-title":"Label-Free MicroRNA Detection Based on Fluorescence Quenching of Gold Nanoparticles with a Competitive Hybridization","volume":"87","author":"Wang","year":"2015","journal-title":"Anal. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1016\/j.bios.2013.10.061","article-title":"Carbon nanotube-based label-free electrochemical biosensor for sensitive detection of miRNA-24","volume":"54","author":"Li","year":"2014","journal-title":"Biosens. Bioelectron."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1373\/clinchem.2013.210542","article-title":"Prognostic significance of metastasis-related microRNAs in early breast cancer patients with a long follow-up","volume":"60","author":"Markou","year":"2014","journal-title":"Clin. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"207","DOI":"10.3389\/fonc.2014.00207","article-title":"miR-21 expression in cancer cells may not predict resistance to adjuvant trastuzumab in primary breast cancer","volume":"4","author":"Nielsen","year":"2014","journal-title":"Front. Oncol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"37269","DOI":"10.18632\/oncotarget.5495","article-title":"MicroRNA-21 links epithelial-to-mesenchymal transition and inflammatory signals to confer resistance to neoadjuvant trastuzumab and chemotherapy in HER2-positive breast cancer patients","volume":"6","author":"Bottai","year":"2015","journal-title":"Oncotarget"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1038\/jhg.2016.89","article-title":"Recent trends in microRNA research into breast cancer with particular focus on the associations between microRNAs and intrinsic subtypes","volume":"62","author":"Kurozumi","year":"2017","journal-title":"J. Hum. Genet."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"R2","DOI":"10.1186\/bcr2803","article-title":"Knockdown of miR-21 in human breast cancer cell lines inhibits proliferation, In Vitro migration and In Vivo tumor growth","volume":"13","author":"Yan","year":"2011","journal-title":"Breast Cancer Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"754","DOI":"10.1021\/acs.analchem.5b03056","article-title":"Quantification of microRNA by DNA\u2212peptide probe and liquid chromatography\u2212tandem mass spectrometry-based quasi-targeted proteomics","volume":"88","author":"Xu","year":"2016","journal-title":"Anal. Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1039\/C7FD00140A","article-title":"SERS-active metal-dielectric nanostructures integrated in microfluidic devices for label-free quantitative detection of miRNA","volume":"205","author":"Novara","year":"2017","journal-title":"Faraday Discuss."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/3\/863\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:57:08Z","timestamp":1760194628000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/3\/863"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,3,15]]},"references-count":43,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2018,3]]}},"alternative-id":["s18030863"],"URL":"https:\/\/doi.org\/10.3390\/s18030863","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,3,15]]}}}