{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T21:10:06Z","timestamp":1774386606638,"version":"3.50.1"},"reference-count":53,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2016,6,13]],"date-time":"2016-06-13T00:00:00Z","timestamp":1465776000000},"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>We developed a new method for detecting S1 nuclease and hydroxyl radicals based on the use of water-soluble conjugated poly[9,9-bis(6,6-(N,N,N-trimethylammonium)-fluorene)-2,7-ylenevinylene-co-alt-2,5-dicyano-1,4-phenylene)] (PFVCN) and tungsten disulfide (WS2) nanosheets. Cationic PFVCN is used as a signal reporter, and single-layer WS2 is used as a quencher with a negatively charged surface. The ssDNA forms complexes with PFVCN due to much stronger electrostatic interactions between cationic PFVCN and anionic ssDNA, whereas PFVCN emits yellow fluorescence. When ssDNA is hydrolyzed by S1 nuclease or hydroxyl radicals into small fragments, the interactions between the fragmented DNA and PFVCN become weaker, resulting in PFVCN being adsorbed on the surface of WS2 and the fluorescence being quenched through fluorescence resonance energy transfer. The new method based on PFVCN and WS2 can sense S1 nuclease with a low detection limit of 5 \u00d7 10\u22126 U\/mL. Additionally, this method is cost-effective by using affordable WS2 as an energy acceptor without the need for dye-labeled ssDNA. Furthermore, the method provides a new platform for the nuclease assay and reactive oxygen species, and provides promising applications for drug screening.<\/jats:p>","DOI":"10.3390\/s16060865","type":"journal-article","created":{"date-parts":[[2016,6,13]],"date-time":"2016-06-13T10:29:22Z","timestamp":1465813762000},"page":"865","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Label-Free Fluorescence Assay of S1 Nuclease and Hydroxyl Radicals Based on Water-Soluble Conjugated Polymers and WS2 Nanosheets"],"prefix":"10.3390","volume":"16","author":[{"given":"Junting","family":"Li","sequence":"first","affiliation":[{"name":"Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi\u2019an 710062, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qi","family":"Zhao","sequence":"additional","affiliation":[{"name":"Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi\u2019an 710062, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanli","family":"Tang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi\u2019an 710062, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,6,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Li, J.J. (2000). Using Molecular Beacons as a Sensitive Fluorescence Assay for Enzymatic Cleavage of Single-Stranded DNA. Nucleic Acids Res., 28.","DOI":"10.1093\/nar\/28.11.e52"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"20745","DOI":"10.1021\/jp065121l","article-title":"Gold Nanoparticle Based Fret Assay for the Detection of DNA Cleavage","volume":"110","author":"Ray","year":"2006","journal-title":"J. Phys. Chem. B"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3011","DOI":"10.1093\/nar\/28.16.3011","article-title":"From DNA Biosensors to Gene Chips","volume":"28","author":"Wang","year":"2000","journal-title":"Nucleic Acids Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/0009-2797(90)90003-6","article-title":"Kinetic Studies of the Hydrolysis of Platinum-DNA Complexes by Nuclease S1","volume":"73","author":"Butour","year":"1990","journal-title":"Chem. Biol. Interact."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"12301","DOI":"10.1039\/c1cc15994a","article-title":"Naked-Eye Sensitive Detection of Nuclease Activity Using Positively-Charged Gold Nanoparticles as Colorimetric Probes","volume":"47","author":"Cao","year":"2011","journal-title":"Chem. Commun."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1016\/j.bios.2013.03.066","article-title":"Potentiometric Sensing of Nuclease Activities and Oxidative Damage of Single-Stranded DNA Using a Polycation-Sensitive Membrane Electrode","volume":"47","author":"Ding","year":"2013","journal-title":"Biosens. Bioelectron."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"14972","DOI":"10.1021\/ja065159b","article-title":"Direct Visualization of Enzymatic Cleavage and Oxidative Damage by Hydroxyl Radicals of Single-Stranded DNA with a Cationic Polythiophene Derivative","volume":"128","author":"Tang","year":"2006","journal-title":"J. Am. Chem. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"8133","DOI":"10.1039\/c1cc12216a","article-title":"DNA-Templated Ensemble for Label-Free and Real-Time Fluorescence Turn-on Detection of Enzymatic\/Oxidative Cleavage of Single-Stranded DNA","volume":"47","author":"Yang","year":"2011","journal-title":"Chem. Commun."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Shen, Q., Nie, Z., Guo, M., Zhong, C.-J., Lin, B., Li, W., and Yao, S. (2009). Simple and Rapid Colorimetric Sensing of Enzymatic Cleavage and Oxidative Damage of Single-Stranded DNA with Unmodified Gold Nanoparticles as Indicator. Chem. Commun., 929\u2013931.","DOI":"10.1039\/b818081d"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2431","DOI":"10.1021\/ac303440d","article-title":"G-Quadruplex-Based Fluorescent Assay of S1 Nuclease Activity and K","volume":"85","author":"Zhou","year":"2013","journal-title":"Anal. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1038\/35030277","article-title":"Cancer: A Radical Approach to Treatment","volume":"407","author":"Cleveland","year":"2000","journal-title":"Nature"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"6604","DOI":"10.1021\/ja0343252","article-title":"Oscillating Formation of 8-Oxoguanine During DNA Oxidation","volume":"125","author":"White","year":"2003","journal-title":"J. Am. Chem. Soc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"9634","DOI":"10.1021\/ja801858e","article-title":"Evidence for Hydroxyl Radical Generation during Lipid (Linoleate) Peroxidation","volume":"130","author":"Frenette","year":"2008","journal-title":"J. Am. Chem. Soc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1016\/j.snb.2015.11.084","article-title":"Highly Selective Chemiluminescence Detection of Hydroxyl Radical Via Increased Pi-Electron Densities of Rhodamine B on Montmorillonite Matrix","volume":"225","author":"Cao","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1256","DOI":"10.1126\/science.6351251","article-title":"Dietary Carcinogens and Anticarcinogens. Oxygen Radicals and Degenerative Diseases","volume":"221","author":"Ames","year":"1983","journal-title":"Science"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1016\/S0891-5849(02)00878-X","article-title":"Oxidative DNA Damage: Assessment of the Role in Carcinogenesis, Atherosclerosis, and Acquired Immunodeficiency Syndrome","volume":"33","author":"Olinski","year":"2002","journal-title":"Free Radic. Biol. Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1102","DOI":"10.1016\/S0891-5849(02)00826-2","article-title":"Free Radical-Induced Damage to DNA: Mechanisms and Measurement","volume":"32","author":"Dizdaroglu","year":"2002","journal-title":"Free Radic. Biol. Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s11746-998-0032-9","article-title":"Free Radicals, Oxidative Stress, and Antioxidants in Human Health and Disease","volume":"75","author":"Aruoma","year":"1998","journal-title":"J. Am. Oil Chem. Soc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4800","DOI":"10.1002\/anie.201001057","article-title":"Colorimetric Detection of Glucose in Rat Brain Using Gold Nanoparticles","volume":"49","author":"Jiang","year":"2010","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6849","DOI":"10.1002\/anie.200901772","article-title":"Ultrasensitive and Selective Colorimetric DNA Detection by Nicking Endonuclease Assisted Nanoparticle Amplification","volume":"48","author":"Xu","year":"2009","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"13537","DOI":"10.1073\/pnas.240460997","article-title":"A Continuous Assay for DNA Cleavage: The Application of \u201cBreak Lights\u201d to Enediynes, Iron-Dependent Agents, and Nucleases","volume":"97","author":"Biggins","year":"2000","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"8431","DOI":"10.1021\/ac801008q","article-title":"Paper-Based Bioassays Using Gold Nanoparticle Colorimetric Probes","volume":"80","author":"Zhao","year":"2008","journal-title":"Anal. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"699","DOI":"10.1038\/nnano.2012.193","article-title":"Electronics and Optoelectronics of Two-Dimensional Transition Metal Dichalcogenides","volume":"7","author":"Wang","year":"2012","journal-title":"Nat. Nanotechnol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3766","DOI":"10.1021\/cr300263a","article-title":"Graphene-Like Two-Dimensional Materials","volume":"113","author":"Xu","year":"2013","journal-title":"Chem. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1038\/nchem.1589","article-title":"The Chemistry of Two-Dimensional Layered Transition Metal Dichalcogenide Nanosheets","volume":"5","author":"Chhowalla","year":"2013","journal-title":"Nat. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"5627","DOI":"10.1021\/nl403270k","article-title":"Origin of Indirect Optical Transitions in Few-Layer MoS2, WS2, and WSe2","volume":"13","author":"Zhao","year":"2013","journal-title":"Nano Lett."},{"key":"ref_27","first-page":"1","article-title":"Electromechanics in MoS2 and WS2: Nanotubes vs. Monolayers","volume":"3","author":"Zibouche","year":"2013","journal-title":"Sci. Rep."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.aca.2015.01.049","article-title":"A Sensitive Fluorescence Turn-on Assay of Bleomycin and Nuclease Using WS2 Nanosheet as an Effective Sensing Platform","volume":"866","author":"Qin","year":"2015","journal-title":"Anal. Chim. Acta"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1002\/adma.201404568","article-title":"Single-Layer Transition Metal Dichalcogenide Nanosheet-Based Nanosensors for Rapid, Sensitive, and Multiplexed Detection of DNA","volume":"27","author":"Zhang","year":"2015","journal-title":"Adv. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1361","DOI":"10.1021\/ac403944c","article-title":"Highly Sensitive and Selective Strategy for Microrna Detection Based on WS2 nanosheet Mediated Fluorescence Quenching and Duplex-Specific Nuclease Signal Amplification","volume":"86","author":"Xi","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"6866","DOI":"10.1039\/C4NR00944D","article-title":"A WS2 Nanosheet Based Sensing Platform for Highly Sensitive Detection of T4 Polynucleotide Kinase and Its Inhibitors","volume":"6","author":"Ge","year":"2014","journal-title":"Nanoscale"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3610","DOI":"10.1021\/ac5002096","article-title":"Establishing Water-Soluble Layered WS2 nanosheet as a Platform for Biosensing","volume":"86","author":"Yuan","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Mulpur, P., Yadavilli, S., Rao, A., Kamisetti, V., and Podila, R. (2016). MoS2\/WS2\/BN-Silver Thin-Film Hybrid Architectures Displaying Enhanced Fluorescence via Surface Plasmon Coupled Emission for Sensing Applications. ACS Sens.","DOI":"10.1021\/acssensors.5b00297"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2411","DOI":"10.1039\/b909065g","article-title":"Water-Soluble Fluorescent Conjugated Polymers and Their Interactions with Biomacromolecules for Sensitive Biosensors","volume":"39","author":"Feng","year":"2010","journal-title":"Chem. Soc. Rev."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4687","DOI":"10.1021\/cr200263w","article-title":"Water-Soluble Conjugated Polymers for Imaging, Diagnosis, and Therapy","volume":"112","author":"Zhu","year":"2012","journal-title":"Chem. Rev."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"12600","DOI":"10.1021\/ja202877q","article-title":"Design and Synthesis of Monofunctionalized, Water-Soluble Conjugated Polymers for Biosensing and Imaging Applications","volume":"133","author":"Traina","year":"2011","journal-title":"J. Am. Chem. Soc."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2154","DOI":"10.1016\/j.bios.2010.09.025","article-title":"DNA Biosensors Based on Water-Soluble Conjugated Polymers","volume":"26","author":"Liu","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"6764","DOI":"10.1021\/ja058075w","article-title":"Quadruplex-to-Duplex Transition of G-Rich Oligonucleotides Probed by Cationic Water-Soluble Conjugated Polyelectrolytes","volume":"128","author":"He","year":"2006","journal-title":"J. Am. Chem. Soc."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1002\/adma.200701637","article-title":"Direct Visualization of Glucose Phosphorylation with a Cationic Polythiophene","volume":"20","author":"Tang","year":"2008","journal-title":"Adv. Mater."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1021\/ac302840t","article-title":"Strategy for Sensor Based on Fluorescence Emission Red Shift of Conjugated Polymers: Applications in Ph Response and Enzyme Activity Detection","volume":"85","author":"Tang","year":"2013","journal-title":"Anal. Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"6433","DOI":"10.1021\/ac500837f","article-title":"Water-Soluble Conjugated Polymer as a Platform for Adenosine Deaminase Sensing Based on Fluorescence Resonance Energy Transfer Technique","volume":"86","author":"Wang","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"9607","DOI":"10.1002\/anie.201103381","article-title":"Rapid, Simple, and High-Throughput Antimicrobial Susceptibility Testing and Antibiotics Screening","volume":"50","author":"Zhu","year":"2011","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"7882","DOI":"10.1002\/anie.200701724","article-title":"Continuous Fluorometric Assays for Acetylcholinesterase Activity and Inhibition with Conjugated Polyelectrolytes","volume":"46","author":"Feng","year":"2007","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3490","DOI":"10.1002\/adma.200700165","article-title":"Cationic Conjugated Polymer\/DNA Complexes for Amplified Fluorescence Assays of Nucleases and Methyltransferases","volume":"19","author":"Feng","year":"2007","journal-title":"Adv. Mater."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1002\/adom.201200026","article-title":"Water-Soluble Conjugated Polymers for Simultaneous Two-Photon Cell Imaging and Two-Photon Photodynamic Therapy","volume":"1","author":"Shen","year":"2013","journal-title":"Adv. Opt. Mater."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"11093","DOI":"10.1002\/anie.201106004","article-title":"Single-Layer Semiconducting Nanosheets: High-Yield Preparation and Device Fabrication","volume":"50","author":"Zeng","year":"2011","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2283","DOI":"10.1039\/C1CS15270J","article-title":"Biological and Chemical Sensors Based on Graphene Materials","volume":"41","author":"Liu","year":"2012","journal-title":"Chem. Soc. Rev."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2644","DOI":"10.1039\/c0cs00079e","article-title":"Graphene Nanosheet: Synthesis, Molecular Engineering, Thin Film, Hybrids, and Energy and Analytical Applications","volume":"40","author":"Guo","year":"2011","journal-title":"Chem. Soc. Rev."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"5511","DOI":"10.1021\/ac100852z","article-title":"Fluorescence Resonance Energy Transfer between Quantum Dots and Graphene Oxide for Sensing Biomolecules","volume":"82","author":"Dong","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.ab.2014.09.011","article-title":"Label-Free Fluorometric Detection of S1 Nuclease Activity by Using Polycytosine Oligonucleotide-Templated Silver Nanoclusters","volume":"468","author":"Wang","year":"2015","journal-title":"Anal. Biochem."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"10233","DOI":"10.1039\/C5NR01409C","article-title":"Plasmon Coupling-Enhanced Two-Photon Photoluminescence of Au@Ag Core\u2013Shell Nanoparticles and Applications in the Nuclease Assay","volume":"7","author":"Yuan","year":"2015","journal-title":"Nanoscale"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"75055","DOI":"10.1039\/C5RA13301G","article-title":"A Dual-Amplification Fluorescent Sensing Platform for Ultrasensitive Assay of Nuclease and ATP Based on Rolling Circle Replication and Exonuclease Iii-Aided Recycling","volume":"5","author":"Liu","year":"2015","journal-title":"RSC Adv."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"18294","DOI":"10.1039\/C4RA01102C","article-title":"Interaction of single-stranded DNA with graphene oxide: Fluorescence study and its application for S1 nuclease detection","volume":"4","author":"He","year":"2014","journal-title":"RSC Adv."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/6\/865\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:25:20Z","timestamp":1760210720000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/6\/865"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,6,13]]},"references-count":53,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2016,6]]}},"alternative-id":["s16060865"],"URL":"https:\/\/doi.org\/10.3390\/s16060865","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,6,13]]}}}