- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
LED visible-light driven label-free photoelectrochemical immunosensor based on WO3/Au/CdS photocatalyst for the sensitive detection of carcinoembryonic antigen
摘要： A ternary WO3/Au/CdS photocatalyst was prepared by reversible redox and ionic adsorption for the first time. The photocatalyst exhibited high photocatalytic activity and good photoelectrochemical (PEC) property in comparison with WO3, CdS, WO3/Au and WO3/CdS, because the localized surface plasmon resonance (LSPR) effect of Au nanoparticles (Au NPs) and the sensitization of CdS benefited the spatial separation of photogenerated electron-hole pairs and the absorption of visible light. Thus, its photocurrent response intensity was quite high, up to about 218-fold of WO3 and 87-fold of CdS under 430 nm LED light irradiation. Based on the large anodic photocurrent and the specific recognition between carcinoembryonic antigen (CEA) and anti-CEA, a novel PEC immunosensor was constructed for the sensitive and selective detection of CEA. Under the selected conditions, the change of photocurrent intensity was linear to the logarithm of CEA concentration over the range from 0.01 to 10 ng/mL, and the detection limit was down to 1 pg/mL. The immunosensor also showed good stability, reproducibility and repeatability. It was successfully applied to the detection of CEA in serum samples.
关键词： Au nanoparticles,WO3,Photoelectrochemical immunosensor,Carcinoembryonic antigen,CdS
更新于2025-11-21 11:01:37
-
Facile synthesis of two-dimensional tailored graphitic carbon nitride with enhanced photoelectrochemical properties through a three-step polycondensation method for photocatalysis and photoelectrochemical immunosensor
摘要： Graphitic carbon nitride (g-C3N4) is an ideal alternative two-dimensional (2D) nanostructure for photocatalysis and photoelectrochemical (PEC) application, while controllably fabricating 2D shaped g-C3N4 nanolayers/nanosheets is still facing challenges. On the basis of temperature-dependent polymorphic characters, herein, a 2D extending g-C3N4 (g-CNS3) is synthesized from dicyandiamide as the precursor by operating the condensation temperature in a continuously three-step thermal polycondensation procedure. The g-CNS3 with film-like morphology showed improved visible-light absorption ability and enhanced PEC performance compared to g-CNS1 synthesized via the traditional one-step thermal polymerization method. Benefiting from its excellent PEC properties, the g-CNS3 exhibited high photocatalytic activity to removal MB with fast kinetics and served as the photoactive layer to construct a PEC immunosensor with high sensitivity and specificity for subgroup J avian leukosis virus detection. A linear range from 102.14 to 103.35 TCID50/mL and a detection limit of 102.08 TCID50/mL were obtained for the PEC immunoassay of the target virus. This work might provide a novel protocol for tailoring shaped 2D g-C3N4 nanosemiconductor with superior properties and shed light on its promising PEC applications.
关键词： Two-dimensional material,Photocurrent response,Graphitic carbon nitride,Photocatalysis,Photoelectrochemical immunosensor
更新于2025-09-23 15:23:52
-
Label-free immunosensors based on a novel multi-amplification signal strategy of TiO2-NGO/Au@Pd hetero-nanostructures
摘要： A label-free electrochemical immunosensor for quantitative detection of human epididymis specific protein 4 antigen (HE4 Ag) was developed by a novel multi-amplification signal system. The multi-amplification signal system was formed by loading bimetallic Au@Pd holothurian-shaped nanoparticles (Au@Pd HSs) on titanium oxide nanoclusters functionalized nitrogen-doped reduced graphene oxide (TiO2-NGO). The Au@Pd HSs were obtained via seed-mediated approach with in-situ grown palladium nanoarms on gold nanorods (Au NRs) surfaces, which possessed good electrocatalysis for hydrogen peroxide (H2O2) reduction and excellent biocompatibility. The TiO2-NGO with the high catalytic activity and large specific surface area was synthesized by hydrothermal method. Using H2O2 as an electrochemically active substrate, the prepared label-free electrochemical immunosensor based on the TiO2-NGO/Au@Pd HSs hetero-nanostructures as the signal amplification platform exhibited excellent selectivity, reproducibility and stability for the detection of HE4 Ag. Meanwhile, the linear range from 40 fM to 60 nM with the detection limit of 13.33 fM (S/N = 3) was obtained, indicating the immunosensor offers a promising method for clinical detection of HE4 Ag.
关键词： Au@Pd nanoparticles,Titanium oxide,Label-free electrochemical immunosensor,Nitrogen-doped reduced graphene oxide,Human epididymis specific protein 4
更新于2025-09-23 15:23:52
-
ZnO/porous carbon composite from a mixed-ligand MOF for ultrasensitive electrochemical immunosensing of C-reactive protein
摘要： Carbon-based nano-composite materials obtained via simple thermolysis of metal-organic framework (MOF) have competitive virtues in accordance of layered porosity, controllable morphologies, and easily functionalizing with other metal/metallic oxides or hetero atoms. These make them directly as high activity catalysts or supports for various electrochemical sensor. Herein, we developed a novel ZnO/porous carbon matrix (ZnO/MPC)-based electrochemical immunosensing through thermolysis of a mixed-ligand MOF (Zn-BDC-TED) for real sample analysis of C-reactive protein. The ZnO/MPC and ionic liquid (IL) composite membrane modified electrode displayed prominent conductivity and biocompatibility for ultrasensitive detection of C-reactive protein (CRP). Subsequently, the step-by-step assembly process of the CRP immunosensor was monitored by electrochemical measurements including cyclic voltammogram (CV) and electrochemical impedance spectra (EIS). After the parameter optimization, the differential pulse voltammetry (DPV) response decreased linearly with the logarithm of CRP levels in an extensive range of 0.01–1000 ng·mL?1, and the detection limit was as low as 5.0 pg·mL?1. Meanwhile, the lable-free immunosensor also showed excellent selectivity, reproducibility and stability. We believe that ZnO/MPC composite and many carbon-based nano-composite materials obtained via simple thermolysis of MOF will be a prospective platform for sensitive detecting other biomarkers.
关键词： ZnO/MPC,C-reactive protein,Electrochemical immunosensor,Pyrolysis,Lable-free
更新于2025-09-23 15:22:29
-
Photoluminescence Immunosensor Based on Bovine Leukemia Virus Proteins Immobilized on the ZnO Nanorods
摘要： Bovine leukaemia virus (BLV) proteins gp51, which are serving as antigens for specific antibodies against BLV proteins (anti-gp51), were applied as biological recognition part in the design of immunosensor devoted for the determination of anti-gp51. The efficiency of the immobilization of BLV proteins gp51 on ZnO nanorod (ZnO-NR) modified glass (ZnO-NR/glass) surface was evaluated. The formation of antigen-antibody complex on the ZnO/glass modified by the BLV proteins gp51 (gp51/ZnO-NR/glass) was investigated by the determination of changes in ZnO photoluminescence. The applicability of gp51/ZnO-NR/glass in the design of photoluminescence based immunosensor was evaluated. Bovine serum albumin (BSA) was applied for the modification of sensing gp51 layer in order to form gp51&BSA layer with advanced selectivity. Polyallylamine hydrochloride (PAH) was applied in order to improve the immobilization of gp51 and BSA based sensing layer (gp51&BSA) on the surface of ZnO-NR/glass. PAH was applied during the formation of gp51&BSA/PAH/ZnO-NR/glass structure. Some aspects of the mechanism of interaction between biomolecules (gp51, bovine serum albumin (BSA) and anti-gp51) and ZnO-NR during the preparation and action of gp51&BSA/ZnO-NR/glass- and gp51&BSA/PAH/ZnO-NR/glass-based immunosensors have been discussed.
关键词： Bovine leukemia virus (BLV),Photoluminescence,Optical immunosensor,ZnO nanorods,Antigen-antibody complex.
更新于2025-09-23 15:22:29
-
Surface-plasmon-coupled chemiluminescence amplification of silver nanoparticles modified immunosensor for high-throughput ultrasensitive detection of multiple mycotoxins
摘要： A novel surface-plasmon-coupled chemiluminescent immunosensor was developed for the detection of multiplex mycotoxins with ultrahigh sensitivity, high throughput and simplicity. The immunosensor was constructed by immobilizing carboxyl modified silver nanoparticles (AgNPs) and bovine serum albumin combined antigens sequentially on the glass chip modified with amino groups. The optical properties of AgNPs could amplify the chemiluminescence (CL) generated on the chip through the surface plasmon resonance phenomenon. Using a competitive immunoassay, the CL signals from all the sensing sites on the chip were collected simultaneously by a charge-coupled device for ultrasensitive analysis of multiple mycotoxins. Citrinin, aflatoxin B1 and ochratoxins A were selected as model analytes. Under optimal conditions, the surface-plasmon-coupled chemiluminescent immunosensor-based method presented wide linear ranges over 4 orders of magnitude and much lower limits of detection than previous work. The assay results of mycotoxins in red yeast rice samples using the proposed method were in good agreement with that using the liquid chromatography-mass spectrometry method. Its high selectivity, high throughput, acceptable stability and accuracy showed broad prospects in mycotoxin monitoring and evaluation of safety on Traditional Chinese Medicine.
关键词： Immunosensor array,Signal amplification,Silver nanoparticle,Multiplex immunoassay,Mycotoxins,Surface-plasmon-coupled chemiluminescence
更新于2025-09-23 15:21:01
-
Development of a ZnCdS@ZnS quantum dotsa??based label-free electrochemiluminescence immunosensor for sensitive determination of aflatoxin B1 in lotus seed
摘要： In this study, we designed a ZnCdS@ZnS quantum dots (QDs)–based label-free electrochemiluminescence (ECL) immunosensor for sensitive determination of aflatoxin B1 (AFB1). A Nafion solution assembled abundant QDs on the surface of a Au electrode as ECL signal probes, with specially coupled anti-AFB1 antibodies as the capturing element. As the reduction reaction between S2O8 2? in the electrolyte and QDs on the electrode led to ECL emission, the decreased ECL signals resulting from target AFB1 in the samples were recorded for quantification. We evaluated electrochemical impedance spectroscopy and ECL measurements along each step in the construction of the proposed immunosensor. After systematic optimization of crucial parameters, the ECL immunosensor exhibited a good sensitivity, with a low detection limit of 0.01 ng/mL for AFB1 in a wide concentration range of 0.05–100 ng/mL. Testing with lotus seed samples confirmed the satisfactory selectivity, stability, and reproducibility of the developed ECL immunosensor for rapid, efficient, and sensitive detection of AFB1 at trace levels in complex matrices. This study provides a powerful and universal analytical platform for a variety of analytes that can be used in broad applications for real-time analysis, such as food and traditional Chinese medicine safety testing, environmental pollution monitoring, and disease diagnostics.
关键词： Electrochemiluminescence immunosensor,Nafion,Lotus seed,Aflatoxin B1,ZnCdS@ZnS quantum dots,Label-free
更新于2025-09-23 15:19:57
-
CdTe@SiO2 signal reporters-based fluorescent immunosensor for quantitative detection of prostate specific antigen
摘要： In this paper, an immunosensor using CdTe@SiO2 core-shell nanoparticles as labels was constructed for highly sensitive detection of prostate-specific antigen (PSA). In this approach, CdTe@SiO2 core-shell nanoparticles were synthesized using the sol-gel method. The additional Cd ions and sulfur source in SiO2 shell can greatly enhance the fluorescence intensity of CdTe nanocrystals. The reason is the formation of CdS-like cluster in SiO2 shell, which reduced the quantum size effect. The obtained CdTe@SiO2 nanoparticles also exhibited excellent biocompatibility, which was ideal for applying in biomarker detection. Furthermore, PSA capture antibodies functionalized magnetic Fe3O4 nanoparticles (Fe3O4-Ab1) were utilized in the proposed immunosensor to capture and enrich the PSA. The captured PSA was then immuno-recognized by CdTe@SiO2 labeled with PSA detection antibodies (CdTe@SiO2-Ab2) by forming the sandwich complex Fe3O4-Ab1/PSA/Ab2-CdTe@SiO2. The construction of this immunosensor was confirmed by fluorescence spectroscopy. The proposed immunosensor showed a good linear relationship between the fluorescent intensity and the target PSA concentration ranging from 0.01 to 5 ng/mL, and a detection limit as low as 0.003 ng/mL was achieved. The sensor also exhibited good specificity to PSA. This highly sensitive and specific immunosensor has great potential to be used in other biological detection.
关键词： Quantum Dots,Core-shell,Prostate Specific Antigen,Immunosensor
更新于2025-09-19 17:15:36
-
Protein-functionalized WO3 nanorods–based impedimetric platform for sensitive and label-free detection of a cardiac biomarker
摘要： We report the development of a sensitive and a label-free electrochemical immunosensing platform for the detection of cardiac biomarker troponin I (cTnI) using tungsten trioxide nanorods (WO3 NRs). The low-temperature hydrothermal technique was employed for the controlled synthesis of WO3 NRs. Thin films of 3-aminopropyltriethoxy saline (APTES)-functionalized WO3 NRs were deposited on indium tin oxide (ITO)-coated glass substrate (0.5 cm × 1 cm) using electrophoretic deposition technique. The covalent immobilization of cTnI antibody onto functionalized WO3 NRs electrode was accomplished using EDC-NHS [1-(3-(dimethylamino)-propyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysulfosuccinimide] chemistry. The structural and morphological characterizations of WO3 NRs and functionalized WO3 NRs were studied using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and electrochemical techniques. The impedimetric response study of the proposed immunosensor demonstrates high sensitivity [6.81 KΩ·mL/(ng·cm2)] in a linear detection range of 0.01–10 ng/mL. The excellent selectivity, good reproducibility, and long-term stability of the proposed immunosensing platform indicate WO3 NRs as a suitable platform for the development of a point-of-care biosensing device for cardiac detection.
关键词： electrochemical impedance spectroscopy,tungsten trioxide nanorods,immunosensor,cardiac biomarker,label-free detection
更新于2025-09-19 17:15:36
-
Photothermal amplified cathodic ZnO quantum dots/Ru(bpy)32+/S2O82- ternary system for ultrasensitive electrochemiluminescence detection of thyroglobulin
摘要： Herein, an ultrasensitive electrochemiluminescence (ECL) immunosensor based on a high performance probe of Nb2CTx MXene immobilized ZnO quantum dots (QDs) was constructed for Thyroglobulin (Tg) detection. ZnO QDs with good biocompatibility and catalytic property was for the first time utilized as coreaction accelerator in Ru(bpy)3 2+/S2O8 2- system and enhanced ECL signal. Specifically, ZnO QDs can facilitate S2O8 2- reduction to generate more SO4 ??, and then reacted with cathodic radical of Ru(bpy)3 2+, realizing 2-fold enhancement in ECL intensity. Additionally, Nb2CTx MXene possesses excellent properties and was used as prominent supporter, improving the loading capacity of Ru(bpy)3 2+ and ZnO QDs, and accelerating the electron transfer, resulting in ECL signal enhancement. Furthermore, Nb2CTx MXene acted as temperature controller and increased the electrode surface temperature by converting laser energy into heat, further amplified ECL signal. Because of the high sensitivity, good specificity and favorable stability, the proposed immunosensor realized sensitive detection of Thyroglobulin and had a great application prospect in bioanalysis and clinical diagnosis.
关键词： ZnO quantum dots,Photothermal amplification,Coreactant accelerator,Nb2CTx MXene,ECL immunosensor
更新于2025-09-19 17:13:59