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  1. Article ; Online: A Sensitive Fluorescent Immunoassay for Prostate Specific Antigen Detection Based on Signal Amplify Strategy of Horseradish Peroxidase and Silicon Dioxide Nanospheres

    Lihua Li / Wenzhi Zhang / Yan Wei / Lizhen Yu / Dexiang Feng

    Journal of Analytical Methods in Chemistry, Vol

    2022  Volume 2022

    Abstract: A simple, sensitive, and fluorescent immunoassay for the detection of prostate-specific antigen (PSA) based on horseradish peroxidase and silicon dioxide nanospheres as a signal amplification strategy has been described. In the design, the primary ... ...

    Abstract A simple, sensitive, and fluorescent immunoassay for the detection of prostate-specific antigen (PSA) based on horseradish peroxidase and silicon dioxide nanospheres as a signal amplification strategy has been described. In the design, the primary antibody (Ab1) of PSA was first immobilized on the 96-well plates via physical adsorption between polystyrene and hydrophobic groups of the antibody molecule. The silicon dioxide nanospheres (SiO2 NSs), with large surface area and good biocompatibility, were loaded with horseradish peroxidase (HRP) and horseradish peroxidase-labeled secondary antibodies (HRP-Ab2) as signal amplification systems. In the presence of PSA, a sandwich-type immunocomplex composed of Ab1-Ag-HRP-Ab2 had been formed. Fluorescence technology was employed to obtain the response signal of the immunoassay in the L-tyrosine and H2O2 systems. Experiment results showed that a strong and stable fluorescent signal at 416 nm (excitation wavelength: 325 nm) was observed, and the changes in fluorescent intensity were related to the levels of PSA. Under the optimal conditions, the relative fluorescence intensity was linear with the logarithm of PSA concentration from 0.03 to 100 ng·mL−1, with a detection limit of 0.01 ng·mL−1 (at a signal/noise ratio of 3). In contrast to other fluorescent immunoassays, the sandwich-type immunoreaction based on the high binding ELISA plates has the advantages of being simple, stable, and easy to operate, high selectivity, small sample quantity, etc., which can be widely used in the selective detection of a variety of targets, from DNA to proteins and small molecules. Such fluorescent immunoassays should be feasible for the fields of molecular diagnosis and other life science fields in the future.
    Keywords Analytical chemistry ; QD71-142
    Subject code 500
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher Hindawi Limited
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Highly Sensitive Immunosensing of Carcinoembryonic Antigen Based on Gold Nanoparticles Dotted PB@PANI Core-Shell Nanocubes as a Signal Probe

    Dexiang Feng / Lingzhi Chen / Ke Zhang / Shuangshuang Zhu / Meichen Ying / Peng Jiang / Menglan Fu / Yan Wei / Lihua Li

    Journal of Analytical Methods in Chemistry, Vol

    2023  Volume 2023

    Abstract: Herein, a method was developed for the sensitive monitoring of carcinoembryonic antigen (CEA) by gold nanoparticles dotted prussian blue@polyaniline core-shell nanocubes (Au NPs/PB@PANI). First, a facile low-temperature method was used to prepare the ... ...

    Abstract Herein, a method was developed for the sensitive monitoring of carcinoembryonic antigen (CEA) by gold nanoparticles dotted prussian blue@polyaniline core-shell nanocubes (Au NPs/PB@PANI). First, a facile low-temperature method was used to prepare the uniform PB@PANI core-shell nanocubes with the assistance of PVP, where PB acted as the electron transfer mediator to provide electrochemical signals, and the PANI with excellent conductivity and desirable chemical stability not only played the role of a protective layer to prevent etching of PB in basic media but also effectively improved electron transfer. Importantly, to further enhance the electrical conductivity and biocompatibility of PB@PANI and to further enhance the electrochemical signal and capture a large amount of Ab2, Au NPs were doped on the surface of PB@PANI to form Au NPs/PB@PANI nanocomposites. Subsequently, benefiting from the advantages of core-shell structure nanoprobes and gold-platinum bimetallic nanoflower (AuPt NF), a sandwich-type electrochemical immunosensor for CEA detection was constructed, which provided a wide linear detection range from 1.0 pg·mL−1 to 100.0 ng·mL−1 and a low detection limit of 0.35 pg·mL−1 via DPV (at 3σ). Moreover, it displayed a satisfactory result when the core-shell structure nanoprobe-based immunosensor was applied to determine CEA in real human serum samples.
    Keywords Analytical chemistry ; QD71-142
    Language English
    Publishing date 2023-01-01T00:00:00Z
    Publisher Hindawi Limited
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Dual‐Pronged Attack

    He Wang / Zhangxin He / Yijian Gao / Dexiang Feng / Xuedong Wei / Yuhua Huang / Jianquan Hou / Shengliang Li / Weijie Zhang

    Advanced Science, Vol 10, Iss 28, Pp n/a-n/a (2023)

    pH‐Driven Membrane‐Anchored NIR Dual‐Type Nano‐Photosensitizer Excites Immunogenic Pyroptosis and Sequester Immune Checkpoint for Enhanced Prostate Cancer Photo‐Immunotherapy

    2023  

    Abstract: Abstract Prostate cancer (PCa) is a frustrating immunogenic “cold” tumor and generally receives unsatisfied immunotherapy outcomes in the clinic. Pyroptosis is an excellent immunogenic cell death form that can effectively activate the antitumor immune ... ...

    Abstract Abstract Prostate cancer (PCa) is a frustrating immunogenic “cold” tumor and generally receives unsatisfied immunotherapy outcomes in the clinic. Pyroptosis is an excellent immunogenic cell death form that can effectively activate the antitumor immune response, promote cytotoxic T‐lymphocyte infiltration, and convert tumors from “cold” to “hot.” However, the in vivo application of pyroptosis drugs is seriously limited, and the upregulation of tumor PD‐L1 caused by photo‐immunotherapy further promotes immune escape. Herein, a new nano‐photosensitizer (YBS‐BMS NPs‐RKC) with pH‐response integrating immunogenic pyroptosis induction and immune checkpoint blockade is developed. The pH‐responsive polymer equipped with the cell membrane anchoring peptide RKC is used as the carrier and further encapsulated with the near‐infrared‐activated semiconductor polymer photosensitizer YBS and a PD‐1/PD‐L1 complex small molecule inhibitor BMS‐202. The pH‐driven membrane‐anchoring and pyroptosis activation of YBS‐BMS NPs‐RKC is clearly demonstrated. In vitro and in vivo studies have shown that this dual‐pronged therapy stimulates a powerful antitumor immune response to suppress primary tumor progression and evokes long‐term immune memory to inhibit tumor relapse and metastasis. This work provides an effective self‐synergistic platform for PCa immunotherapy and a new idea for developing more biocompatible photo‐controlled pyroptosis inducers.
    Keywords immunotherapy ; membrane anchoring ; prostate cancer ; pyroptosis ; type I photosensitizer ; Science ; Q
    Subject code 570
    Language English
    Publishing date 2023-10-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article: Simultaneous detection of two tumor markers using silver and gold nanoparticles decorated carbon nanospheres as labels

    Li, Lihua / Dexiang Feng / Yuzhong Zhang

    Analytical biochemistry. 2016 July 15, v. 505

    2016  

    Abstract: In this work, a multiplexed electrochemical immunosensor was developed for sensitive detection of carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) using silver nanoparticles (Ag NPs) or gold nanoparticles (Au NPs) coated-carbon nanospheres (CNSs) ... ...

    Abstract In this work, a multiplexed electrochemical immunosensor was developed for sensitive detection of carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) using silver nanoparticles (Ag NPs) or gold nanoparticles (Au NPs) coated-carbon nanospheres (CNSs) as labels. CNSs were employed as the carrier for the immobilization of nanoparticles (Ag NPs or Au NPs), thionine (Thi), and secondary antibodies (Ab2) due to their good monodispersity and uniform structure. Au NPs reduced graphene oxide (rGO) nanocomposites were used as sensing substrate for assembling two primary antibodies (Ab1). In the presence of target proteins, two labels were attached onto the surface of the rGO/Au NPs nanocomposites via a sandwich immunoreaction. Two distinguishable peaks, one at +0.16 V (corresponding to Ag NPs) and another at −0.33 V (corresponding to Thi), were obtained in differential pulse voltammetry (DPV). The peak difference was approximately 490 mV, indicating that CEA and AFP can be simultaneously detected in a single run. Under optimal conditions, the peak currents were linearly related to the concentrations of CEA or AFP in the range of 0.01–80 ng ml−1. The detection limits of CEA and AFP were 2.8 and 3.5 pg ml−1, respectively (at a signal-to-noise ratio of 3). Moreover, when the immunosensor was applied to serum samples, the results obtained were in agreement with those of the reference method, indicating that the immunosensor would be promising in the application of clinical diagnosis and screening of biomarkers.
    Keywords antibodies ; antigens ; biomarkers ; blood serum ; carbon ; detection limit ; electrochemistry ; graphene oxide ; immunosensors ; nanocomposites ; nanogold ; nanoparticles ; nanosilver ; nanospheres ; proteins ; screening ; silver
    Language English
    Dates of publication 2016-0715
    Size p. 59-65.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 1110-1
    ISSN 1096-0309 ; 0003-2697
    ISSN (online) 1096-0309
    ISSN 0003-2697
    DOI 10.1016/j.ab.2016.04.014
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Bonn / Germany

    Z 70/124: Show issues

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  5. Article: Luminescence energy transfer detection of PSA in red region based on Mn2+-enhanced NaYF4:Yb, Er upconversion nanorods

    Zhang, Jianguo / Dexiang Feng / Hongqi Chen / Lun Wang / Ni Gao / Shaozhen Wang

    Biosensors & bioelectronics. 2015 Oct. 15, v. 72

    2015  

    Abstract: A new turn-on luminescence energy transfer (LET) system has been designed for the detection of prostate specific antigen (PSA, a cancer marker) that utilizes Mn2+-enhanced long wavelength luminescence NaYF4:Yb, Er upconversion nanorods as the donor and ... ...

    Abstract A new turn-on luminescence energy transfer (LET) system has been designed for the detection of prostate specific antigen (PSA, a cancer marker) that utilizes Mn2+-enhanced long wavelength luminescence NaYF4:Yb, Er upconversion nanorods as the donor and gold nanorods as the acceptor. The Mn2+-doped NaYF4:Yb,Er upconversion luminescence nanorods with an emission peak located in the red region were synthesized. The presence of Mn2+ markedly increased the luminescence intensity over that of the NaYF4:Yb, Er upconversion nanomaterials (excited by a 980nm continuous wavelength laser). The surfaces of Mn2+-doped NaYF4:Yb, Er upconversion nanorods were modified with poly(acrylic acid). Antibodies against prostate specific antigen were bound to the surface of the carboxyl-functionalized upconversion nanorods, which acted as the energy donor in this LET system. Gold nanorods with an absorption band at ~666nm were synthesized by the seed growth method, acted as the energy acceptor. The emission band of the upconversion nanorods overlapped well with the absorption band of the gold nanorods. The luminescence was quenched because of the electrostatic interactions that shortened the distance between the donor (negatively charged) and the accepter (positively charged).When the PSA antigen was added into the system, the energy acceptor and the energy donors were separated because the binding affinity between PSA and anti-PSA was greater than the electrostatic interactions, and thereby the luminescence was recovered. The linear range of detecting PSA was from 0.1172 to 18.75ng/mL (R=0.995), with a limit of detection for PSA as low as 0.1129ng/mL. The method was successfully applied to the sensing of PSA in human serum samples.
    Keywords absorption ; antibodies ; antigens ; binding capacity ; biosensors ; blood serum ; detection limit ; electrostatic interactions ; energy transfer ; gold ; humans ; light intensity ; luminescence ; manganese ; nanorods ; neoplasms ; polyacrylic acid ; wavelengths
    Language English
    Dates of publication 2015-1015
    Size p. 282-287.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1011023-9
    ISSN 1873-4235 ; 0956-5663
    ISSN (online) 1873-4235
    ISSN 0956-5663
    DOI 10.1016/j.bios.2015.05.024
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2275: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

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  6. Article: Graphene quantum dots: Highly active bifunctional nanoprobes for nonenzymatic photoluminescence detection of hydroquinone

    He, Yuezhen / Dexiang Feng / Feng Gao / Hongqi Chen / Jian Sun / Lun Wang

    Biosensors & bioelectronics. 2015 Dec. 15, v. 74

    2015  

    Abstract: In this paper, a simple and sensitive photoluminescence method is developed for the hydroquinone quantitation by using graphene quantum dots which simultaneously serve as a peroxidase-mimicking catalyst and a photoluminescence indicator. In the presence ... ...

    Abstract In this paper, a simple and sensitive photoluminescence method is developed for the hydroquinone quantitation by using graphene quantum dots which simultaneously serve as a peroxidase-mimicking catalyst and a photoluminescence indicator. In the presence of dissolved oxygen, graphene quantum dots with intrinsic peroxidase-mimicking catalytic activity can catalyze the oxidation of hydroquinone to produce p-benzoquinone, an intermediate, which can efficiently quench graphene quantum dots' photoluminescence. Based on this effect, a novel fluorescent platform is proposed for the sensing of hydroquinone, and the detection limit of 5nM is found.
    Keywords benzoquinones ; biosensors ; catalysts ; catalytic activity ; detection limit ; dissolved oxygen ; fluorescence ; graphene ; hydroquinone ; oxidation ; photoluminescence ; quantum dots
    Language English
    Dates of publication 2015-1215
    Size p. 418-422.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1011023-9
    ISSN 1873-4235 ; 0956-5663
    ISSN (online) 1873-4235
    ISSN 0956-5663
    DOI 10.1016/j.bios.2015.07.006
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2275: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

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