{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,25]],"date-time":"2025-10-25T21:52:42Z","timestamp":1761429162906,"version":"build-2065373602"},"reference-count":57,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2016,8,23]],"date-time":"2016-08-23T00:00:00Z","timestamp":1471910400000},"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 report a protocol of CdS-labeled sandwich-type amperometric bioanalysis with high sensitivity, on the basis of simultaneous chemical-dissolution\/cathodic-enrichment of the CdS quantum dot biolabel and anodic stripping voltammetry (ASV) detection of Cd directly on the bioelectrode. We added a microliter droplet of 0.1  M aqueous HNO3 to dissolve CdS on the bioelectrode and simultaneously achieved the potentiostatic cathodic preconcentration of Cd by starting the potentiostatic operation before HNO3 addition, which can largely increase the ASV signal. Our protocol was used for immunoanalysis and aptamer-based bioanalysis of several proteins, giving limits of detection of 4.5 fg\u00b7mL\u22121 for human immunoglobulin G, 3.0 fg\u00b7mL\u22121 for human carcinoembryonic antigen (CEA), 4.9 fg\u00b7mL\u22121 for human \u03b1-fetoprotein (AFP), and 0.9 fM for thrombin, which are better than many reported results. The simultaneous and sensitive analysis of CEA and AFP at two screen-printed carbon electrodes was also conducted by our protocol.<\/jats:p>","DOI":"10.3390\/s16091342","type":"journal-article","created":{"date-parts":[[2016,8,23]],"date-time":"2016-08-23T10:18:55Z","timestamp":1471947535000},"page":"1342","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Sensitive Bioanalysis Based on in-Situ Droplet Anodic Stripping Voltammetric Detection of CdS Quantum Dots Label after Enhanced Cathodic Preconcentration"],"prefix":"10.3390","volume":"16","author":[{"given":"Xiaoli","family":"Qin","sequence":"first","affiliation":[{"name":"Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Linchun","family":"Wang","sequence":"additional","affiliation":[{"name":"Liuzhou Traditional Chinese Medicine Hospital, Liuzhou 545001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qingji","family":"Xie","sequence":"additional","affiliation":[{"name":"Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,8,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2228","DOI":"10.1021\/ja060005h","article-title":"Quantum-Dot\/Aptamer-Based Ultrasensitive Multi-Analyte Electrochemical Biosensor","volume":"128","author":"Hansen","year":"2006","journal-title":"J. Am. Chem. Soc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1283","DOI":"10.1038\/ncomms2292","article-title":"Multiplexed volumetric bar-chart chip for point-of-care diagnostics","volume":"3","author":"Song","year":"2012","journal-title":"Nat. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1002\/anie.201005246","article-title":"Amplified Detection of DNA through an Autocatalytic and Catabolic DNAzyme-Mediated Process","volume":"50","author":"Wang","year":"2011","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1038\/nprot.2013.058","article-title":"Enzyme-linked immunospot assays for direct ex vivo measurement of vaccine-induced human humoral immune responses in blood","volume":"8","author":"Saletti","year":"2013","journal-title":"Nat. Protoc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"6897","DOI":"10.1021\/acs.analchem.6b01625","article-title":"Lab-on-a-Membrane Foldable Devices for Duplex Drop-Volume Electrochemical Biosensing Using Quantum Dot Tags","volume":"88","author":"Kokkinos","year":"2016","journal-title":"Anal. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Li, Z., Xin, Y., Wu, W., Fu, B., and Zhang, Z. (2016). Topotactic Conversion of Copper(I) Phosphide Nanowires for Sensitive Electrochemical Detection of H2O2 Release from Living Cells. Anal. Chem.","DOI":"10.1021\/acs.analchem.6b01637"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"7915","DOI":"10.1002\/anie.201102941","article-title":"Nanostructured Immunosensor for Attomolar Detection of Cancer Biomarker Interleukin-8 Using Massively Labeled Superparamagnetic Particles","volume":"50","author":"Munge","year":"2011","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_8","first-page":"1","article-title":"Attomolar Detection of a Cancer Biomarker Protein in Serum by Surface Plasmon Resonance Using Superparamagnetic Particle Labels","volume":"49","author":"Krishnan","year":"2010","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2403","DOI":"10.1021\/ja3089857","article-title":"Photoinduced Electron Transfer of DNA\/Ag Nanoclusters Modulated by G-Quadruplex\/Hemin Complex for the Construction of Versatile Biosensors","volume":"135","author":"Zhang","year":"2013","journal-title":"J. Am. Chem. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1172\/JCI104130","article-title":"Immunoassay of endogenous plasma insulin in man","volume":"39","author":"Yalow","year":"1960","journal-title":"J. Clin. Investig."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1170","DOI":"10.1021\/ac00284a003","article-title":"Enzyme Immunoassays of Eicosanoids Using Acetylcholine Esterase as Label: An Alternative to Radioimmunoassay","volume":"57","author":"Pradelles","year":"1985","journal-title":"Anal. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1600","DOI":"10.1021\/ac802345z","article-title":"Enzyme-Functionalized Silica Nanoparticles as Sensitive Labels in Biosensing","volume":"81","author":"Wu","year":"2009","journal-title":"Anal. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"6104","DOI":"10.1021\/ac300997q","article-title":"Enzyme-Linked Small-Molecule Detection Using Split Aptamer Ligation","volume":"84","author":"Sharma","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2720","DOI":"10.1016\/j.bios.2010.09.031","article-title":"ZnO quantum dot labeled immunosensor for carbohydrate antigen 19-9","volume":"26","author":"Gu","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1021\/ac203184g","article-title":"Highly Sensitive Photoelectrochemical Immunoassay with Enhanced Amplification Using Horseradish Peroxidase Induced Biocatalytic Precipitation on a CdS Quantum Dots Multilayer Electrode","volume":"84","author":"Zhao","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2780","DOI":"10.1021\/ja711298b","article-title":"A One-Step Homogeneous Immunoassay for Cancer Biomarker Detection Using Gold Nanoparticle Probes Coupled with Dynamic Light Scattering","volume":"130","author":"Liu","year":"2008","journal-title":"J. Am. Chem. Soc."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7602","DOI":"10.1002\/anie.200800169","article-title":"Semiconductor Quantum Dots for Bioanalysis","volume":"47","author":"Gill","year":"2008","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6783","DOI":"10.1021\/cr100420s","article-title":"Lung Cancer and Its Early Detection Using Biomarker-Based Biosensors","volume":"111","author":"Arya","year":"2011","journal-title":"Chem. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3184","DOI":"10.1039\/c3cs35528d","article-title":"Biosensors: Sense and Sensibility","volume":"42","author":"Turner","year":"2013","journal-title":"Chem. Soc. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"685","DOI":"10.1021\/ac202878q","article-title":"Electrochemical Sensors and Biosensors","volume":"84","author":"Kimmel","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4311","DOI":"10.1039\/C5SC00891C","article-title":"Simple electrochemical sensing of attomolar proteins using fabricated complexes with enhanced surface binding avidity","volume":"6","author":"Li","year":"2015","journal-title":"Chem. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1038\/nchem.2270","article-title":"An electrochemical clamp assay for direct, rapid analysis of circulating nucleic acids in serum","volume":"7","author":"Das","year":"2015","journal-title":"Nat. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"7810","DOI":"10.1021\/ac301438v","article-title":"Ultrasensitive Multianalyte Electrochemical Immunoassay Based on Metal Ion Functionalized Titanium Phosphate Nanospheres","volume":"84","author":"Feng","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1039\/b211987k","article-title":"Cadmium sulfide nanocluster-based electrochemical stripping detection of DNA hybridization","volume":"128","author":"Zhu","year":"2003","journal-title":"Analyst"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"4302","DOI":"10.1021\/ac200564r","article-title":"Quantum Dot Layer-by-Layer Assemblies as Signal Amplification Labels for Ultrasensitive Electronic Detection of Uropathogens","volume":"83","author":"Xiang","year":"2011","journal-title":"Anal. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1016\/j.bios.2011.12.035","article-title":"Highly sensitive electrochemical detection of potential cytotoxicity of CdSe\/ZnS quantum dots using neural cell chip","volume":"32","author":"Kim","year":"2012","journal-title":"Biosens. Bioelectron."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"4371","DOI":"10.1002\/adfm.201100616","article-title":"A Novel Nanoparticle-Based Disposable Electrochemical Immunosensor for Diagnosis of Exposure to Toxic Organophosphorus Agents","volume":"21","author":"Lu","year":"2011","journal-title":"Adv. Funct. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1042","DOI":"10.1021\/ja067024b","article-title":"A Target-Responsive Electrochemical Aptamer Switch (TREAS) for Reagentless Detection of Nanomolar ATP","volume":"129","author":"Zuo","year":"2007","journal-title":"J. Am. Chem. Soc."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1021\/ac3029486","article-title":"Distance-Dependent Electron Transfer at Passivated Electrodes Decorated by Gold Nanoparticles","volume":"85","author":"Barfidokht","year":"2013","journal-title":"Anal. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"8540","DOI":"10.1039\/C5CC01439E","article-title":"Ultrasensitive Electrochemical Immunoassay of Proteins based on in Situ Duple Amplification of Gold Nanoparticle Biolabel Signals","volume":"51","author":"Qin","year":"2015","journal-title":"Chem. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2855","DOI":"10.1021\/acs.jpcc.5b12004","article-title":"Ultrasensitive Immunoassay of Proteins Based on Gold Label\/Silver Staining, Galvanic Replacement Reaction Enlargement, and In Situ Microliter-Droplet Anodic Stripping Voltammetry","volume":"120","author":"Qin","year":"2016","journal-title":"J. Phys. Chem. C"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"914","DOI":"10.1016\/j.bios.2016.01.024","article-title":"In situ microliter-droplet anodic stripping voltammetry of copper stained on the gold label after galvanic replacement reaction enlargement for ultrasensitive immunoassay of proteins","volume":"79","author":"Qin","year":"2016","journal-title":"Biosens. Bioelectron."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2708","DOI":"10.1021\/ac202959d","article-title":"Magnetic Bead-Sensing-Platform-Based Chemiluminescence Resonance Energy Transfer and Its Immunoassay Application","volume":"84","author":"Qin","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1472","DOI":"10.1021\/jp9092767","article-title":"Chemical\/Biochemical Preparation of New Polymeric Bionanocomposites with Enzyme Labels Immobilized at High Load and Activity for High-Performance Electrochemical Immunoassay","volume":"114","author":"Fu","year":"2010","journal-title":"J. Phys. Chem. C"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"8494","DOI":"10.1021\/ac070923d","article-title":"Versatile Immunosensor Using CdTe Quantum Dots as Electrochemical and Fluorescent Labels","volume":"79","author":"Cui","year":"2007","journal-title":"Anal. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5521","DOI":"10.1021\/ac000781m","article-title":"An Electrochemical Metalloimmunoassay Based on a Colloidal Gold Label","volume":"72","author":"Dequaire","year":"2000","journal-title":"Anal. Chem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2726","DOI":"10.1021\/ac103283p","article-title":"Ultrasensitive Multiplexed Immunoassay with Electrochemical Stripping Analysis of Silver Nanoparticles Catalytically Deposited by Gold Nanoparticles and Enzymatic Reaction","volume":"83","author":"Lai","year":"2011","journal-title":"Anal. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2989","DOI":"10.1021\/ac100036p","article-title":"Sensitive Immunosensor for Cancer Biomarker Based on Dual Signal Amplification Strategy of Graphene Sheets and Multienzyme Functionalized Carbon Nanospheres","volume":"82","author":"Du","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"10492","DOI":"10.1021\/ac302853y","article-title":"Dual-Signal Amplification Strategy for Ultrasensitive Photoelectrochemical Immunosensing of \u03b1-Fetoprotein","volume":"84","author":"Li","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"11047","DOI":"10.1039\/c1cc14024h","article-title":"A facile and sensitive immunoassay for the detection of alpha-fetoprotein using gold-coated magnetic nanoparticle clusters and dynamic light scattering","volume":"47","author":"Chun","year":"2011","journal-title":"Chem. Commum."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1021\/ja108788p","article-title":"Fluorescence Resonance Energy Transfer Inhibition Assay for \u03b1-Fetoprotein Excreted during Cancer Cell Growth Using Functionalized Persistent Luminescence Nanoparticles","volume":"133","author":"Wu","year":"2011","journal-title":"J. Am. Chem. Soc."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3055","DOI":"10.1039\/C1CC16571B","article-title":"Label-free electrochemiluminescent immunosensor for \u03b1-fetoprotein: Performance of Nafion\u2013carbon nanodots nanocomposite films as antibody carriers","volume":"48","author":"Dai","year":"2012","journal-title":"Chem. Commum."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1052","DOI":"10.1039\/C2CC37675J","article-title":"A branched electrode based electrochemical platform: Towards new label-free and reagentless simultaneous detection of two biomarkers","volume":"49","author":"Kong","year":"2013","journal-title":"Chem. Commum."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1016\/j.bios.2012.02.061","article-title":"Highly stable electrochemical immunosensor for carcinoembryonic antigen","volume":"35","author":"Sun","year":"2012","journal-title":"Biosens. Bioelectron."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"4578","DOI":"10.1021\/ac400226n","article-title":"Plasma-Enhanced Antibody Immobilization for the Development of a Capillary-Based Carcinoembryonic Antigen Immunosensor Using Laser-Induced Fluorescence Spectroscopy","volume":"85","author":"Yu","year":"2013","journal-title":"Anal. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"6999","DOI":"10.1021\/ac0610560","article-title":"Flow-Through Multianalyte Chemiluminescent Immunosensing System with Designed Substrate Zone-Resolved Technique for Sequential Detection of Tumor Markers","volume":"78","author":"Fu","year":"2006","journal-title":"Anal. Chem."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3899","DOI":"10.1002\/adfm.201200544","article-title":"Electrogenerated Chemiluminescence from a Phenyleneethynylene Derivative and its Ultrasensitive Immunosensing Application Using a Nanotubular Mesoporous Pt-Ag Alloy for Signal Amplification","volume":"22","author":"Yan","year":"2012","journal-title":"Adv. Funct. Mater."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.bios.2011.07.063","article-title":"A label-free immunosensor based on modified mesoporous silica for simultaneous determination of tumor markers","volume":"29","author":"Lin","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2811","DOI":"10.1021\/ac203261x","article-title":"Novel Magnetic Fe3O4@CdSe Composite Quantum Dot-Based Electrochemiluminescence Detection of Thrombin by a Multiple DNA Cycle Amplification Strategy","volume":"84","author":"Jie","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2520","DOI":"10.1039\/b801055b","article-title":"Ultrasensitive colorimetric detection of protein by aptamer-Au nanoparticles conjugates based on a dot-blot assay","volume":"22","author":"Wang","year":"2008","journal-title":"Chem. Commum."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"11768","DOI":"10.1021\/ja046970u","article-title":"Aptamer-Functionalized Au Nanoparticles for the Amplified Optical Detection of Thrombin","volume":"126","author":"Pavlov","year":"2004","journal-title":"J. Am. Chem. Soc."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1624","DOI":"10.1016\/j.bios.2008.01.029","article-title":"Electrochemical impedance spectroscopy for study of aptamer-thrombin interfacial interactions","volume":"23","author":"Li","year":"2008","journal-title":"Biosens. Bioelectron."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/j.bios.2013.02.004","article-title":"Aptamer\/thrombin\/aptamer-AuNPs sandwich enhanced surface plasmon resonance sensor for the detection of subnanomolar thrombin","volume":"47","author":"Bai","year":"2013","journal-title":"Biosens. Bioelectron."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"2339","DOI":"10.1016\/j.bios.2008.12.002","article-title":"A novel method for the detection of point mutation in DNA using single-base-coded CdS nanoprobes","volume":"24","author":"Ye","year":"2009","journal-title":"Biosens. Bioelectron."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"2072","DOI":"10.1021\/ja311367t","article-title":"DNAzyme Footprinting: Detecting Protein-Aptamer Complexation on Surfaces by Blocking DNAzyme Cleavage Activity","volume":"135","author":"Chen","year":"2013","journal-title":"J. Am. Chem. Soc."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"6408","DOI":"10.1002\/anie.200604524","article-title":"Electronic Aptamer-Based Sensors","volume":"46","author":"Willner","year":"2007","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"5456","DOI":"10.1002\/anie.200500989","article-title":"Label-Free Electronic Detection of Thrombin in Blood Serum by Using an Aptamer-Based Sensor","volume":"44","author":"Xiao","year":"2005","journal-title":"Angew. Chem. Int. 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