{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,20]],"date-time":"2025-12-20T22:04:13Z","timestamp":1766268253054,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2015,4,24]],"date-time":"2015-04-24T00:00:00Z","timestamp":1429833600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003407","name":"Ministero dell\u2019Istruzione, dell\u2019Universit\u00e0 e della Ricerca","doi-asserted-by":"publisher","award":["RBPR05JH2P"],"award-info":[{"award-number":["RBPR05JH2P"]}],"id":[{"id":"10.13039\/501100003407","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Optical fiber sensors, thanks to their compactness, fast response and real-time measurements, have a large impact in the fields of life science research, drug discovery and medical diagnostics. In recent years, advances in nanotechnology have resulted in the development of nanotools, capable of entering the single cell, resulting in new  nanobiosensors useful for the detection of biomolecules inside living cells. In this paper, we provide an application of a nanotip coupled with molecular beacons (MBs) for the detection of DNA. The MBs were characterized by hybridization studies with a complementary target to prove their functionality both free in solution and immobilized onto a solid support. The solid support chosen as substrate for the immobilization of the MBs was a 30 nm tapered tip of an optical fiber, fabricated by chemical etching. With this set-up promising results were obtained and a limit of detection (LOD) of 0.57 nM was reached, opening up the possibility of using the proposed nanotip to detect mRNAs inside the cytoplasm of living cells.<\/jats:p>","DOI":"10.3390\/s150509666","type":"journal-article","created":{"date-parts":[[2015,4,24]],"date-time":"2015-04-24T10:01:59Z","timestamp":1429869719000},"page":"9666-9680","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Optical Fiber Nanotips Coated with Molecular Beacons for DNA Detection"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0002-2977","authenticated-orcid":false,"given":"Ambra","family":"Giannetti","sequence":"first","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3759-7512","authenticated-orcid":false,"given":"Andrea","family":"Barucci","sequence":"additional","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"}]},{"given":"Franco","family":"Cosi","sequence":"additional","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"}]},{"given":"Stefano","family":"Pelli","sequence":"additional","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"},{"name":"Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Piazza del Viminale 1,  00184 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1660-9833","authenticated-orcid":false,"given":"Sara","family":"Tombelli","sequence":"additional","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7822-4459","authenticated-orcid":false,"given":"Cosimo","family":"Trono","sequence":"additional","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2689-5952","authenticated-orcid":false,"given":"Francesco","family":"Baldini","sequence":"additional","affiliation":[{"name":"CNR\u2014Institute of Applied Physics \"Nello Carrara\", Via Madonna del Piano 10,  50019 Sesto Fiorentino (FI), Italy"}]}],"member":"1968","published-online":{"date-parts":[[2015,4,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.sab.2007.11.027","article-title":"Nanosensing at the single cell level","volume":"63","year":"2008","journal-title":"Spectrochim. Acta Part B At. Spectrosc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4484","DOI":"10.1016\/j.bios.2011.05.007","article-title":"Bifunctional electro-optical nanoprobe to real-time detect local biochemical processes in single cells","volume":"26","author":"Zheng","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1126\/science.1088525","article-title":"Diffusion dynamics of glycine receptors revealed by single-quantum dot tracking","volume":"302","author":"Dahan","year":"2003","journal-title":"Science"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1893","DOI":"10.1523\/JNEUROSCI.3847-05.2006","article-title":"Quantum Dot Applications to Neuroscience: New Tools for Probing Neurons and Glia","volume":"26","author":"Pathak","year":"2006","journal-title":"J. Neurosci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"868","DOI":"10.1016\/j.actbio.2013.10.039","article-title":"A novel carboxymethyl chitosan\u2013quantum dot-based intracellular probe for Zn2+ ion sensing in prostate cancer cells","volume":"10","author":"Ma","year":"2014","journal-title":"Acta Biomater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.jconrel.2013.03.012","article-title":"Mesenchymal stem cells as delivery vehicle of porphyrin loaded nanoparticles: Effective photoinduced in vitro killing of osteosarcoma","volume":"168","author":"Duchi","year":"2013","journal-title":"J. Control Release"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"6181","DOI":"10.1007\/s00216-013-7086-8","article-title":"Oligonucleotide optical switches for intracellular sensing","volume":"405","author":"Giannetti","year":"2013","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1382","DOI":"10.1002\/anie.200703039","article-title":"Inorganic Nanoparticles as Carriers of Nucleic Acids into Cells","volume":"47","author":"Sokolova","year":"2008","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1002\/jbio.201000002","article-title":"Gold nanorods as new nanochromophores for photothermal therapies","volume":"4","author":"Ratto","year":"2010","journal-title":"J. Biophoton."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1449","DOI":"10.1016\/j.bios.2010.07.079","article-title":"Development of a novel method to detect intrinsic mRNA in a living cell by using a molecular beacon-immobilized nanoneedle","volume":"26","author":"Kihara","year":"2010","journal-title":"Biosens. Bioelectron."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1039\/B9NR00231F","article-title":"Nanoneedle: A multifunctional tool for biological studies in living cells","volume":"2","author":"Yum","year":"2010","journal-title":"Nanoscale"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1016\/j.nantod.2012.08.002","article-title":"Recent progress in cell surface nanoscopy: Light and force in the near-field","volume":"7","year":"2012","journal-title":"Nano Today"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1548","DOI":"10.1016\/j.bios.2009.11.008","article-title":"Single living cell detection of telomerase over-expression for cancer detection by an optical fibre nanobiosensor","volume":"25","author":"Zheng","year":"2010","journal-title":"Biosen. Bioelectron."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"5082","DOI":"10.1021\/ac100074n","article-title":"Optical Detection of Single Cell Lactate Release for Cancer Metabolic Analysis","volume":"82","author":"Zheng","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1002\/jrs.3100","article-title":"Nanoprobes for intracellular and single cell surface-enhanced Raman spectroscopy (SERS)","volume":"43","author":"Vitol","year":"2012","journal-title":"J. Raman Spectrosc."},{"key":"ref_16","first-page":"288","article-title":"Ion Concentrations in Live Cells from Highly Selective Ion Correlations Fluorescent Nano-Sensors for Sodium","volume":"1","author":"Brasuel","year":"2002","journal-title":"IEEE Proc."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1049\/ip-opt:19971269","article-title":"Development of a fibre optic micro-optrode for intracellular pH measurements","volume":"144","author":"McCulloch","year":"1997","journal-title":"IEE Proc. Optoelectron."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4124","DOI":"10.1021\/ac0102718","article-title":"A Real-Time Ratiometric Method for the Determination of Molecular Oxygen Inside Living Cells Using Sol\u2212Gel-Based Spherical Optical Nanosensors with Applications to Rat C6 Glioma","volume":"73","author":"Xu","year":"2001","journal-title":"Anal. Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"764","DOI":"10.1038\/77337","article-title":"Antibody-based nanoprobe for measurement of a fluorescent analyte in a single cell","volume":"18","author":"Alarie","year":"2000","journal-title":"Nat. Biotechnol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"918","DOI":"10.1007\/s00216-005-3256-7","article-title":"Fibre-optic nanosensors for single-cell monitoring","volume":"382","author":"Kasili","year":"2005","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.nano.2005.10.012","article-title":"Nanoprobes and nanobiosensors for monitoring and imaging individual living cells","volume":"2","author":"Kasili","year":"2006","journal-title":"Nanomed. Nanotechnol. Biol. Med."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Zhang, Y., Dhawan, A., and Vo-Dinh, T. (2011). Design and Fabrication of Fibre-Optic Nanoprobes for Optical Sensing. Nanoscale Res. Lett., 6.","DOI":"10.1007\/s11671-010-9744-5"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Zhang, J., Laiwalla, F., Kim, J.A., Urabe, H., Van Wagenen, R., Song, Y.-K., Connors, B.W., Zhang, F., Deisseroth, K., and Nurmikko, A.V. (2009). Integrated device for optical stimulation and spatiotemporal electrical recording of neural activity in light-sensitized brain tissue. J. Neural Eng., 6.","DOI":"10.1088\/1741-2560\/6\/5\/055007"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1038\/nbt0396-303","article-title":"Molecular beacons: Probes that fluoresce upon hybridization","volume":"14","author":"Tyagi","year":"1996","journal-title":"Nat. Biotechnol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1006\/abio.2000.4656","article-title":"Molecular Beacons for DNA Biosensors with Micrometer to Submicrometer Dimensions","volume":"283","author":"Liu","year":"2000","journal-title":"Anal. Biochem."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Monroy-Contreras, R., and Vaca, L. (2011). Molecular Beacons: Powerful Tools for Imaging RNA in Living Cells. J. Nucleic Acids, 2011.","DOI":"10.4061\/2011\/741723"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1002\/wnan.52","article-title":"Molecular beacons and related probes for intracellular RNA imaging","volume":"2","author":"Santangelo","year":"2010","journal-title":"Wiley Interdiscip. Rev. Nanomed. Nanobiotechnol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"395","DOI":"10.7150\/thno.5935","article-title":"Molecular Beacons of Xeno-Nucleic Acid for Detecting Nucleic Acid","volume":"3","author":"Wang","year":"2013","journal-title":"Theranostics"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"15357","DOI":"10.3390\/molecules181215357","article-title":"Fluorescent Probes for Nucleic Acid Visualization in Fixed and Live Cells","volume":"18","author":"Boutorine","year":"2013","journal-title":"Molecules"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"7761","DOI":"10.1063\/1.481382","article-title":"Scanning near-field optical microscopy with aperture probes: Fundamentals and applications","volume":"112","author":"Hecht","year":"2000","journal-title":"J. Chem. Phys."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Carpi, C., Fogli, S., Giannetti, A., Adinolfi, B., Tombelli, S., Da Pozzo, E., Vanni, A., Martinotti, E., Martini, C., and Breschi, M.C. (2014). Theranostic properties of a survivin-directed molecular beacon in human melanoma cells. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0114588"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1016\/j.proeng.2014.11.645","article-title":"Complex nanostructures based on oligonucleotide optical switches and nanoparticles for intracellular mRNA sensing and silencing","volume":"87","author":"Adinolfi","year":"2014","journal-title":"Proc. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Nitin, N., Santangelo, P.J., Kim, G., Nie, S., and Bao, G. (2004). Peptide-linked molecular beacons for efficient delivery and rapid mRNA detection in living cells. Nucleic Acids Res., 32.","DOI":"10.1093\/nar\/gnh063"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Santangelo, P.J., Nix, B., Tsourkas, A., and Bao, G. (2004). Dual FRET molecular beacons for mRNA detection in living cells. Nucleic Acids Res., 32.","DOI":"10.1093\/nar\/gnh062"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"11210","DOI":"10.1002\/chem.201100658","article-title":"Simultaneous Detection of Intracellular Tumor mRNA with Bi-Color Imaging Based on a Gold Nanoparticle\/Molecular Beacon","volume":"17","author":"Qiao","year":"2011","journal-title":"Chem. Eur. J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1016\/j.ejogrb.2011.06.038","article-title":"Detection of survivin expression in cervical cancer cells using molecular beacon imaging: New strategy for the diagnosis of cervical cancer","volume":"159","author":"Xue","year":"2011","journal-title":"Eur. J. Obstet. Gynecol. Reprod. Biol."},{"key":"ref_37","unstructured":"Barucci, A., Cosi, F., Pelli, S., Soria, S., Nunzi Conti, G., Giannetti, A., and Righini, G. (2014). Method of Fabricating Structures, Starting from Material Rods. (PCT\/EP2014\/071743), Patent Pending."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Barucci, A., Cosi, F., Giannetti, A., Pelli, S., Griffini, D., Insinna, M., Salvadori, S., Tiribilli, B., and Righini, G.C. (2015). Optical fibre nanotips fabricated by a dynamic chemical etching for sensing applications. J. Appl. Phys., 117.","DOI":"10.1063\/1.4906854"},{"key":"ref_39","first-page":"289","article-title":"Stability of a Viscous Liquid Contained between Two Rotating Cylinders","volume":"223","author":"Taylor","year":"1923","journal-title":"Philosoph. Trans. R. Soc. London Ser. A Contain. Pap. Math. Phys. Charact."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1017\/S0022112086002513","article-title":"Flow regimes in a circular Couette system with independently rotating cylinders","volume":"164","author":"Andereck","year":"1986","journal-title":"J. Fluid Mech."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Tombelli, S., Ballestri, M., Giambastiani, G., Giannetti, A., Guerrini, A., Sotgiu, G., Trono, C., Tuci, G., Varchi, G., and Baldini, F. (2013). Oligonucleotide switches and nanomaterials for intracellular mRNA sensing. Proc. SPIE, 8798.","DOI":"10.1117\/12.2033185"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Pini, V., Tiribilli, B., Gambi, C.M.C., and Vassalli, M. (2010). Dynamical characterization of vibrating AFM cantilevers forced by photothermal excitation. Phys. Rev. B., 81.","DOI":"10.1103\/PhysRevB.81.054302"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1007\/978-1-4614-3860-1_11","article-title":"Intracellular nanosensing and nanodelivery by PMMA nanoparticles","volume":"162","author":"Giannetti","year":"2014","journal-title":"Lect. Notes Electri. Eng."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Giannetti, A., Tombelli, S., Trono, C., Ballestri, M., Giambastiani, G., Guerrini, A., Sotgiu, G., Tuci, G., Varchi, G., and Baldini, F. (2013). Intracellular delivery of molecular beacons by PMMA nanoparticles and carbon nanotubes for mRNA sensing. Proc. SPIE., 8596.","DOI":"10.1117\/12.2007391"},{"key":"ref_45","unstructured":"Lechuga, L.M. (2007, January 25\u201327). New frontiers in optical biosensing. Proceedings of the 13th European Conference on Integrated Optics (ECIO 2007), Copenhagen, Denmark."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/j.bioelechem.2004.04.008","article-title":"Direct immobilization of DNA probes for the development of affinity biosensors","volume":"66","author":"Mannelli","year":"2005","journal-title":"Bioelectrochemistry"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1021\/ac051478u","article-title":"Label-free DNA detection based on modified conducting polypyrrole films at microelectrodes","volume":"78","author":"Yamanaka","year":"2006","journal-title":"Anal. Chem."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/5\/9666\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:45:19Z","timestamp":1760215519000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/5\/9666"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,4,24]]},"references-count":47,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2015,5]]}},"alternative-id":["s150509666"],"URL":"https:\/\/doi.org\/10.3390\/s150509666","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2015,4,24]]}}}