CdS:Mn quantum dot-functionalized g-C3N4 nanohybrids as signal-generation tags for photoelectrochemical immunoassay of prostate specific antigen coupling DNAzyme concatamer with enzymatic biocatalytic precipitation.

A new photoelectrochemical (PEC) immunosensor based on Mn-doped CdS quantum dots (CdS:Mn QDs) on g-C3N4 nanosheets was developed for the sensitive detection of prostate specific antibody (PSA) in biological fluids. The signal derived from the as-synthesized Cd:Mn QDs-functionalized g-C3N4 nanohybrids via a hydrothermal method and was amplified through DNAzyme concatamers on gold nanoparticles accompanying enzymatic biocatalytic precipitation. Experimental results by UV-vis absorption spectra and photoluminescence revealed that CdS:Mn QDs/g-C3N4 nanohybrids exhibited higher photocurrent than those of CdS:Mn QDs and g-C3N4 alone. Upon addition of target PSA, a sandwich-type immunoreaction was carried out between capture antibodies and the labeled detection antibodies. Accompanying introduction of gold nanoparticles, the labeled initiator strands on the AuNPs triggered hybridization chain reaction and the formation of DNAzyme concatamers in the presence of hemin. The formed DNAzyme catalyzed 4-chloro-1-naphthol (4-CN) to produce an insoluble/insulating precipitate on the Mn:CdS QDs/g-C3N4, and blocked the light harvesting of Mn:CdS QDs/g-C3N4, thus resulting in the decreasing photocurrent. Under optimal conditions, the immunosensor exhibited good photocurrent responses for determination of target PSA, and allowed detection of PSA at a concentration as low as 3.8pgmL-1. The specificity, reproducibility and precision of this system were acceptable. Significantly, this methodology was further evaluated for analyzing human serum samples, giving well-matched results with referenced PSA enzyme-linked immunosorbent assay (ELISA) method.

[1]  Jing‐Juan Xu,et al.  A ratiometric electrochemiluminescence detection for cancer cells using g-C3N4 nanosheets and Ag-PAMAM-luminol nanocomposites. , 2016, Biosensors & bioelectronics.

[2]  Yi Lin,et al.  Metal-enhanced fluorescent dye-doped silica nanoparticles and magnetic separation: A sensitive platform for one-step fluorescence detection of prostate specific antigen. , 2017, Biosensors & bioelectronics.

[3]  Tatsuro Endo,et al.  Quantum dot-based immunosensor for the detection of prostate-specific antigen using fluorescence microscopy. , 2007, Talanta.

[4]  Z. Zou,et al.  Photodegradation of rhodamine B and methyl orange over boron-doped g-C3N4 under visible light irradiation. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[5]  Ping Liu,et al.  Constructing atomic layer g-C₃N₄-CdS nanoheterojunctions with efficiently enhanced visible light photocatalytic activity. , 2014, Physical chemistry chemical physics : PCCP.

[6]  Wei Zhao,et al.  Using silver nanocluster/graphene nanocomposite to enhance photoelectrochemical activity of CdS:Mn/TiO2 for highly sensitive signal-on immunoassay. , 2016, Biosensors & bioelectronics.

[7]  Peng Wu,et al.  Long-lived charge carriers in Mn-doped CdS quantum dots for photoelectrochemical cytosensing. , 2015, Chemistry.

[8]  D. Tang,et al.  Enzymatic Oxydate-Triggered Self-Illuminated Photoelectrochemical Sensing Platform for Portable Immunoassay Using Digital Multimeter. , 2016, Analytical chemistry.

[9]  Bing Sun,et al.  Effective signal-on photoelectrochemical immunoassay of subgroup J avian leukosis virus based on Bi2S3 nanorods as photosensitizer and in situ generated ascorbic acid for electron donating. , 2014, Biosensors & bioelectronics.

[10]  Feng Yan,et al.  Biomedical and clinical applications of immunoassays and immunosensors for tumor markers , 2007 .

[11]  C. Cao,et al.  Tubular graphitic-C3N4: a prospective material for energy storage and green photocatalysis , 2013 .

[12]  Dan Wu,et al.  Cathodic electrochemiluminescence immunosensor based on nanocomposites of semiconductor carboxylated g-C3N4 and graphene for the ultrasensitive detection of squamous cell carcinoma antigen. , 2014, Biosensors & bioelectronics.

[13]  D. Tang,et al.  In Situ Generation of Electron Donor to Assist Signal Amplification on Porphyrin-Sensitized Titanium Dioxide Nanostructures for Ultrasensitive Photoelectrochemical Immunoassay. , 2015, ACS applied materials & interfaces.

[14]  T. Stamey,et al.  Ultrasensitive radioimmunoassay of prostate-specific antigen. , 1992, Clinical chemistry.

[15]  Arne Thomas,et al.  Cubic mesoporous graphitic carbon(IV) nitride: an all-in-one chemosensor for selective optical sensing of metal ions. , 2010, Angewandte Chemie.

[16]  M. Antonietti,et al.  Phosphorus-doped carbon nitride solid: enhanced electrical conductivity and photocurrent generation. , 2010, Journal of the American Chemical Society.

[17]  Deming Kong,et al.  Optimization of strand displacement amplification-sensitized G-quadruplex DNAzyme-based sensing system and its application in activity detection of uracil-DNA glycosylase. , 2016, Biosensors & bioelectronics.

[18]  Jing‐Juan Xu,et al.  Joint enhancement strategy applied in ECL biosensor based on closed bipolar electrodes for the detection of PSA. , 2016, Talanta.

[19]  Wei-Wei Zhao,et al.  Photoelectrochemical DNA biosensors. , 2014, Chemical reviews.

[20]  Binbin Chang,et al.  Novel C3N4–CdS composite photocatalysts with organic–inorganic heterojunctions: in situ synthesis, exceptional activity, high stability and photocatalytic mechanism , 2013 .

[21]  Wei-Wei Zhao,et al.  In situ enzymatic ascorbic acid production as electron donor for CdS quantum dots equipped TiO2 nanotubes: a general and efficient approach for new photoelectrochemical immunoassay. , 2012, Analytical chemistry.

[22]  Dan Wu,et al.  Facile fabrication of an aptasensor for thrombin based on graphitic carbon nitride/TiO2 with high visible-light photoelectrochemical activity. , 2016, Biosensors & bioelectronics.

[23]  Qingming Shen,et al.  Chronic myeloid leukemia drug evaluation using a multisignal amplified photoelectrochemical sensing platform. , 2014, Analytical chemistry.

[24]  Bing Zhang,et al.  Hemin/G-quadruplex-based DNAzyme concatamers as electrocatalysts and biolabels for amplified electrochemical immunosensing of IgG1. , 2012, Chemical communications.

[25]  Jun-Jie Zhu,et al.  Dual-signal amplification strategy for ultrasensitive photoelectrochemical immunosensing of α-fetoprotein. , 2012, Analytical chemistry.

[26]  Jun‐Jie Zhu,et al.  Ultrasensitive electrochemical immunoassay based on cadmium ion-functionalized PSA@PAA nanospheres. , 2010, Biosensors & bioelectronics.

[27]  Yuming Dong,et al.  An ultrasensitive and universal photoelectrochemical immunoassay based on enzyme mimetics enhanced signal amplification. , 2015, Biosensors & bioelectronics.

[28]  Hui‐Ming Cheng,et al.  Graphene‐Like Carbon Nitride Nanosheets for Improved Photocatalytic Activities , 2012 .

[29]  Qingming Shen,et al.  "Signal-on" photoelectrochemical biosensor for sensitive detection of human T-Cell lymphotropic virus type II DNA: dual signal amplification strategy integrating enzymatic amplification with terminal deoxynucleotidyl transferase-mediated extension. , 2015, Analytical chemistry.

[30]  Jingdong Zhang,et al.  Photoelectrochemical sensing of catechol based on CdS-DNA-pristine graphene nanocomposite film , 2015 .

[31]  M. Antonietti,et al.  A metal-free polymeric photocatalyst for hydrogen production from water under visible light. , 2009, Nature materials.

[32]  Nan Zhang,et al.  Simultaneous Photoelectrochemical Immunoassay of Dual Cardiac Markers Using Specific Enzyme Tags: A Proof of Principle for Multiplexed Bioanalysis. , 2016, Analytical chemistry.

[33]  Jun Wang,et al.  Single‐Layered Graphitic‐C3N4 Quantum Dots for Two‐Photon Fluorescence Imaging of Cellular Nucleus , 2014, Advanced materials.

[34]  Klaus Müllen,et al.  Graphene-based carbon nitride nanosheets as efficient metal-free electrocatalysts for oxygen reduction reactions. , 2011, Angewandte Chemie.

[35]  Feng Li,et al.  A versatile immobilization-free photoelectrochemical biosensor for ultrasensitive detection of cancer biomarker based on enzyme-free cascaded quadratic amplification strategy. , 2016, Biosensors & bioelectronics.

[36]  Zhenli Qiu,et al.  CdTe/CdSe quantum dot-based fluorescent aptasensor with hemin/G-quadruplex DNzyme for sensitive detection of lysozyme using rolling circle amplification and strand hybridization. , 2017, Biosensors & bioelectronics.

[37]  D. Tang,et al.  Hemin/G-quadruplex-based DNAzyme concatamers for in situ amplified impedimetric sensing of copper(II) ion coupling with DNAzyme-catalyzed precipitation strategy. , 2015, Biosensors & bioelectronics.

[38]  M. Antonietti,et al.  Polymeric Graphitic Carbon Nitride for Heterogeneous Photocatalysis , 2012 .

[39]  Dianping Tang,et al.  Plasmonic AuNP/g-C3N4 Nanohybrid-based Photoelectrochemical Sensing Platform for Ultrasensitive Monitoring of Polynucleotide Kinase Activity Accompanying DNAzyme-Catalyzed Precipitation Amplification. , 2015, ACS applied materials & interfaces.