{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T20:56:51Z","timestamp":1772657811676,"version":"3.50.1"},"reference-count":45,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2015,9,8]],"date-time":"2015-09-08T00:00:00Z","timestamp":1441670400000},"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>The work being reported is the first electrochemical sensor for tetrodotoxin (TTX). It was developed on a glassy carbon electrodes (C) that was modified with  poly(4-styrenesolfonic acid)-doped polyaniline film (PANI\/PSSA). An amine-end functionalized TTX-binding aptamer, 5\u2032-NH2-AAAAATTTCACACGGGTGCCTCGGCTGTCC-3\u2032 (NH2-Apt), was grafted via covalent glutaraldehyde (glu) cross-linking. The resulting aptasensor (C\/\/PANI+\/PSSA-glu-NH2-Apt) was interrogated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in sodium acetate buffer (NaOAc,  pH 4.8) before and after 30 min incubation in standard TTX solutions. Both CV and EIS results confirmed that the binding of the analyte to the immobilized aptamer modulated the electrochemical properties of the sensor: particularly the charge transfer resistance (Rct) of the PANI+\/PSSA film, which served as a signal reporter. Based on the Rct calibration curve of the TTX aptasensor, the values of the dynamic linear range (DLR), sensitivity and limit of detection (LOD) of the sensor were determined to be 0.23\u20131.07 ng\u00b7mL\u22121 TTX,  134.88 \u00b1 11.42 \u03a9\u00b7ng\u00b7mL\u22121 and 0.199 ng\u00b7mL\u22121, respectively. Further studies are being planned to improve the DLR as well as to evaluate selectivity and matrix effects in  real samples.<\/jats:p>","DOI":"10.3390\/s150922547","type":"journal-article","created":{"date-parts":[[2015,9,8]],"date-time":"2015-09-08T11:59:54Z","timestamp":1441713594000},"page":"22547-22560","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Aptameric Recognition-Modulated Electroactivity  of Poly(4-Styrenesolfonic Acid)-Doped Polyaniline Films  for Single-Shot Detection of Tetrodotoxin"],"prefix":"10.3390","volume":"15","author":[{"given":"Gertrude","family":"Fomo","sequence":"first","affiliation":[{"name":"SensorLab, Chemistry Department, University of the Western Cape, P. Bag X17, Bellville,  Cape Town 7535, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tesfaye","family":"Waryo","sequence":"additional","affiliation":[{"name":"SensorLab, Chemistry Department, University of the Western Cape, P. Bag X17, Bellville,  Cape Town 7535, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christopher","family":"Sunday","sequence":"additional","affiliation":[{"name":"SensorLab, Chemistry Department, University of the Western Cape, P. Bag X17, Bellville,  Cape Town 7535, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Abd","family":"Baleg","sequence":"additional","affiliation":[{"name":"SensorLab, Chemistry Department, University of the Western Cape, P. Bag X17, Bellville,  Cape Town 7535, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Priscilla","family":"Baker","sequence":"additional","affiliation":[{"name":"SensorLab, Chemistry Department, University of the Western Cape, P. Bag X17, Bellville,  Cape Town 7535, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6102-0433","authenticated-orcid":false,"given":"Emmanuel","family":"Iwuoha","sequence":"additional","affiliation":[{"name":"SensorLab, Chemistry Department, University of the Western Cape, P. Bag X17, Bellville,  Cape Town 7535, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,9,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1081\/TXR-100102537","article-title":"Pharmacology of tetrodotoxin","volume":"20","author":"Narahashi","year":"2001","journal-title":"J. Toxicol. Toxin Rev."},{"key":"ref_2","first-page":"11","article-title":"Distribution and origin of tetrodotoxin","volume":"20","author":"Miyazawa","year":"2001","journal-title":"Toxin Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1068","DOI":"10.1007\/s00216-006-0522-2","article-title":"Study of a toxin-alkaline phosphatase conjugate for the development of an immunosensor for tetrodotoxin determination","volume":"385","author":"Neagu","year":"2006","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_4","first-page":"41","article-title":"Detection of tetrodotoxin by High Performance Liquid Chromatography in Lined-Moon Shell and Puffer Fish","volume":"9","author":"Chen","year":"1998","journal-title":"Acta Zool. Taiwan."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.snb.2007.07.136","article-title":"Quantitative detection of tetrodotoxin (TTX) by a surface plasmon resonance (SPR) sensor","volume":"130","author":"Taylor","year":"2008","journal-title":"Sens. Actuators B Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1021\/jf103779k","article-title":"Evaluation of Surface Plasmon Resonance Biosensors for Detection of Tetrodotoxin in Food Matrices and Comparison to Analytical Methods","volume":"59","author":"Yakes","year":"2011","journal-title":"J. Agric. Food Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1590\/S0103-50532003000200003","article-title":"Electrochemical Sensors: A Powerful Tool in Analytical Chemistry","volume":"14","author":"Stradiotto","year":"2003","journal-title":"J. Braz. Chem. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Moretto, L., and Kalcher, K. (2014). Environmental Analysis by Electrochemical Sensors and Biosensors: Fundamentals, Springer-Verlag. Nanostructure Science and Technology.","DOI":"10.1007\/978-1-4939-0676-5"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/S1389-0352(99)00003-3","article-title":"Structure, recognition and discrimination in RNA aptamer complexes with cofactors, amino acids, drugs and aminoglycoside antibiotics","volume":"74","author":"Patel","year":"2000","journal-title":"Rev. Mol. Biotechnol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1007\/BF02940259","article-title":"Aptamers as functional nucleic acids: In vitro selection and biotechnological applications","volume":"8","author":"You","year":"2003","journal-title":"Biotechnol. Bioprocess Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1093\/abbs\/gmp022","article-title":"In vitro selection of high-affinity DNA aptamers for streptavid","volume":"41","author":"Wang","year":"2009","journal-title":"Acta Biochim. Biophys. Sin."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1007\/s00216-006-0826-2","article-title":"Methods developed for SELEX","volume":"387","author":"Gopinath","year":"2007","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_13","unstructured":"Ketai, G. (2006). Biology, der Eberhard Karls Universit\u00e4t T\u00fcbingen."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"599","DOI":"10.1177\/1087057106288491","article-title":"Novel approach to analyzing RNA aptamer-protein interactions: Toward further applications of aptamers","volume":"11","author":"Hwang","year":"2006","journal-title":"J. Biomol. Screen."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6973","DOI":"10.1021\/ac049158i","article-title":"Protein-protein interaction studies based on molecular aptamers by affinity capillary electrophoresis","volume":"76","author":"Huang","year":"2004","journal-title":"Anal. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1007\/s00216-010-3922-2","article-title":"Aptamer-based electrochemical approach to the detection of thrombin by modification of gold nanoparticles","volume":"398","author":"Li","year":"2010","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/j.colsurfb.2010.04.017","article-title":"A sensitive nanoporous gold-based electrochemical aptasensor for thrombin detection","volume":"79","author":"Qiu","year":"2010","journal-title":"Colloids Surf B Biointerfaces"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"9176","DOI":"10.1039\/c004133e","article-title":"Label-free RNA aptamer-based capacitive biosensor for the detection of C-reactive protein","volume":"12","author":"Qureshi","year":"2010","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1016\/j.foodcont.2010.11.005","article-title":"Enzyme-linked aptamer assays (ELAAs), based on a competition format for a rapid and sensitive detection of ochratoxin A in wine","volume":"22","author":"Barthelmebs","year":"2011","journal-title":"Food Control"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3494","DOI":"10.1016\/j.bios.2011.01.032","article-title":"PVP-coated graphene oxide for selective determination of ochratoxin A via quenching fluorescence of free aptamer","volume":"26","author":"Sheng","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2456","DOI":"10.1016\/j.bios.2006.09.015","article-title":"In vitro selection of DNA aptamer against abrin toxin and aptamer-based abrin direct detection","volume":"22","author":"Tang","year":"2007","journal-title":"Biosens. Bioelectron."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/j.bioeng.2007.03.003","article-title":"Aptamers-based assays for diagnostics, environmental and food analysis","volume":"24","author":"Tombelli","year":"2007","journal-title":"Biomol. Eng."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"61","DOI":"10.4236\/jbnb.2010.11008","article-title":"Immobilized molecules using biomaterials and nanobiotechnology","volume":"1","author":"Elnashar","year":"2010","journal-title":"J. Biomater. Nanobiotechnol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1016\/j.sna.2010.10.009","article-title":"Synthesis and performance evaluation of thin film PPy-PVDF multilayer electroactive polymer actuators","volume":"165","author":"Gaihre","year":"2011","journal-title":"Sens. Actuators A Phys."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Millner, P.A., Hays, H.C.W., Vakurov, A., Pchelintsev, N.A., Billah, M.M., and Rodgers, M.A. (2009). Nanostructured Transducer Surfaces for Electrochemical Biosensor Construction\u2014Interfacing the Sensing Component with the Electrode, in Seminars in Cell & Developmental Biology, University of Leeds.","DOI":"10.1016\/j.semcdb.2009.01.011"},{"key":"ref_26","unstructured":"Fomo, G. (2015). Ionophoric and Aptameric Recognition-Modulated Electroactive Polyaniline Films for the Determination of Tetrodotoxin, in Chemistry, University of the Western Cape."},{"key":"ref_27","first-page":"347","article-title":"Screening and Structure Analysis of the Aptamer Against Tetrodotoxin","volume":"2","author":"Shao","year":"2012","journal-title":"J. Chin. Inst. Food Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"790","DOI":"10.2144\/04375RV01","article-title":"Glutaraldehyde: Behavior in aqueous solution, reaction with proteins, and application to enzyme crosslinking","volume":"37","author":"Migneault","year":"2004","journal-title":"BioTechniques"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4006","DOI":"10.1016\/j.bios.2011.03.014","article-title":"Polyaniline Langmuir-Blodgett film based aptasensor for ochratoxin A detection","volume":"26","author":"Prabhakar","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3031","DOI":"10.1016\/S1452-3981(23)13933-2","article-title":"Electrochemical Properties of Nanotubes and Nanomicelles from Novel Polyaniline and Derivative","volume":"7","author":"Klink","year":"2012","journal-title":"Int. J. Electrochem. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1016\/j.electacta.2013.12.150","article-title":"Graphenated tantalum (IV) oxide and poly (4-styrene sulphonic acid)-doped polyaniline nanocomposite as cathode material in an electrochemical capacitor","volume":"128","author":"Njomo","year":"2014","journal-title":"Electrochim. Acta"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/S1388-2481(02)00263-1","article-title":"An extraordinary electrocatalytic reduction of oxygen on gold nanoparticles-electrodeposited gold electrodes","volume":"4","author":"Ohsaka","year":"2002","journal-title":"Electrochem. Commun."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"4808","DOI":"10.1021\/jp711853q","article-title":"Polyaniline based nucleic acid sensor","volume":"11","author":"Prabhakar","year":"2008","journal-title":"J. Phys. Chem. B"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"497","DOI":"10.6028\/jres.105.040","article-title":"Using Impedance Spectroscopy to Assess the Viability of the Rapid Chloride Test for Determining Concrete Conductivity","volume":"105","author":"Snyder","year":"2000","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Yoo, H.J., and Hoof, C.V. (2011). Integrated Circuits and Systems, Massachusetts Institute of Technology. Bio-Medical CMOS ICs.","DOI":"10.1007\/978-1-4419-6597-4"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1016\/S0041-0101(98)00116-0","article-title":"Application of immunoaffinity chromatography for detection of tetrodotoxin from urine samples of poisoned patients","volume":"37","author":"Kentar","year":"1999","journal-title":"Toxicon"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.forsciint.2011.10.026","article-title":"Determination and validation of tetrodotoxin in human whole blood using hydrophilic interaction liquid chromatography-tandem mass spectroscopy and its application","volume":"217","author":"Cho","year":"2012","journal-title":"Forensic Sci. Int."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2215","DOI":"10.1109\/JSEN.2011.2178065","article-title":"Development of Microcontroller Applied to Chlorine Ion Measurement System","volume":"12","author":"Chou","year":"2012","journal-title":"IEEE Sens. J."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.jchromb.2005.12.036","article-title":"Determination of tetrodotoxin in human urine and blood using C18 cartridge column, ultrafiltration and LC-MS","volume":"832","author":"Tsai","year":"2006","journal-title":"J. Chromatogr. B"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1248\/yakushi1947.120.10_825","article-title":"Recent advance of studies on fugu toxin","volume":"10","author":"Matsui","year":"2000","journal-title":"Yakugaku Zasshi"},{"key":"ref_41","first-page":"1556","article-title":"Identification of Tetrodotoxin in a Marine Gastropod (Nassarius glans) Responsible for Human Morbidity and Mortality in Taiwan","volume":"8","author":"Hwang","year":"2005","journal-title":"J. Food Prot."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2439","DOI":"10.1081\/AL-100107525","article-title":"Sensitive analysis of tetrodotoxin in human plasma by solid-phase extractions and gas chromatography\/mass spectrometry","volume":"34","author":"Shunsuke","year":"2001","journal-title":"Anal. Lett."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1016\/j.toxicon.2004.07.008","article-title":"Use of high performance liquid chromatography to measure tetrodotoxin in serum and urine of poisoned patients","volume":"44","author":"Schneider","year":"2004","journal-title":"Toxicon"},{"key":"ref_44","unstructured":"Ji, R., Wang, J., Luo, X., Jiang, T., and Zhang, J. (2002). Determination of tetrodotoxin in puffer fishes using monoclonal antibody-based direct competitive inhibition enzyme-linked immunosorbent assay. Chin. J. Food Hyg., 5."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1016\/j.snb.2010.02.049","article-title":"Gold nanoparticle probe-based immunoassay as a new tool for tetrodotoxin detection in puffer fish tissues","volume":"146","author":"Zhou","year":"2010","journal-title":"Sens. Actuators B Chem."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/9\/22547\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:48:07Z","timestamp":1760215687000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/9\/22547"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,9,8]]},"references-count":45,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2015,9]]}},"alternative-id":["s150922547"],"URL":"https:\/\/doi.org\/10.3390\/s150922547","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,9,8]]}}}