- 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
-
Wet NH3-Triggered NH2-MIL-125(Ti) Structural Switch for Visible Fluorescence Immunoassay Impregnated on Paper
摘要： This work has looked to explore an innovative and powerful visible fluorescence immunoassay method through wet NH3-triggered structural change of NH2-MIL-125(Ti) impregnated on paper for the detection of carcinoembryonic antigen (CEA). Gold nanoparticles heavily functionalized with glutamate dehydrogenase (GDH) and secondary antibody were used for generation of wet NH3 with a sandwiched immunoassay format. Paper-based analytical device (PAD) coated with NH2-MIL-125(Ti) exhibited good visible fluorescence intensity through wet NH3-triggeried structural change with high accuracy and reproducibility. Moreover, NH2-MIL-125(Ti)-based PAD displayed two visual modes of fluorescence color and physical color with naked eyes, and allowed the detection of CEA at a concentration as low as 0.041 ng mL-1. Importantly, the PAD-based assay provides promise for use in the mass production of miniaturized devices and opens new opportunities for protein diagnostics and biosecurity.
关键词： paper-based analytical device,NH2-MIL-125(Ti),visible fluorescence immunoassay,wet NH3,carcinoembryonic antigen
更新于2025-09-23 15:21:21
-
Detection of Tumor Marker Using ZnO@Reduced Graphene Oxide Decorated with Alkaline Phosphatase-Labelled Magnetic Beads
摘要： Magnetic bead-based electrochemical enzyme-linked immunoassay (MB-eElisa) represents an attractive approach to develop cost-effective systems that are suitable for sensing complex biological samples. Its sensitivity essentially depends on the transduction efficiency of enzyme catalytic reactions into electrochemical responses. Here, an ultrahigh signal-to-noise alkaline phosphatase (ALP)-based MB-eElisa system is developed with a renewable zinc oxide-reduced graphene oxide nanocomposite modified carbon paste electrode (ZnO@rGO/CPE). This biosensing system employs one antibody decorated MBs (MB-Ab1) to capture a model tumor marker - carcinoembryonic antigen (CEA) - from samples, while other antibody coated gold nanoparticles-ALP bioconjugates (Ab2-AuNPs-ALP) convert 1-naphthyl phosphate (1-NPP) into electroactive 1-naphthol (1-NP). Beneficial from the unique electrochemical properties of a ZnO@rGO/CPE, inlcuding nearly zero background and significantly enhanced responses toward the hydrolyzed 1-NP in the presence of trace surfactants, the MB-eElisa system detects selectively CEA in a calibration range of 0.01-6.0 ng mL-1 and with a detection limit of 4.0 pg mL-1 (S/N = 3). Such a system was further applied to the detection of CEA in serum samples of cancer patients. The combination of MB-based ALP-linked immunoassay with a ZnO@rGO/CPE thus establishes a reusable and inexpensive electrochemical sensing platform for the rapid and sensitive detection of ultratrace biomarkers in complex biological samples.
关键词： Enzyme-linked immunoassay,Carcinoembryonic antigen,Alkaline phosphatase,Magnetic beads,Electrochemical biosensors
更新于2025-09-11 14:15:04
-
Colorimetric Analysis of Carcinoembryonic Antigen Using Highly Catalytic Gold Nanoparticles-Decorated MoS <sub/>2</sub> Nanocomposites
摘要： Sensitive detection of carcinoembryonic antigen (CEA) is very important for early detection and cancer therapy monitoring. We utilized the highly catalytic activity of MoS2-gold nanoparticles (MoS2-AuNPs) nanocomposites to construct a colorimetric immunoassay for CEA detection, which could catalyze sodium borohydride (NaBH4) to reduce 4-nitrophenol (4-NP) and make the yellow solution colorless. MoS2-AuNPs nanocomposites could e?ciently load antibodies (Ab1 and Ab2) because of their good biocompatibility and high adsorption ability, forming Ab1-MoS2-AuNPs nanoprobes for capturing CEA and Ab2-MoS2-AuNPs nanoprobes for catalytic reaction. It should be pointed out that Ab2-MoS2-AuNPs nanoprobes retained high catalytic activity because no blocking agent was used to block the catalytic sites. After the formation of the classical “sandwich” structure, parts of Ab2-MoS2-AuNPs nanoprobes remained in the supernatant after centrifugation, making the catalytic reaction occur and obtaining a colorless solution. As expected, a linear function between absorbance peak intensity and the logarithm of 5 pg/mL?10 ng/mL CEA was observed, and the detection limit was obtained as 0.5 pg/mL. This colorimetric immunosensor showed acceptable selectivity and repeatability for CEA detection, which could be successfully employed to detect CEA in serum.
关键词： nanoprobe,colorimetric,carcinoembryonic antigen,molybdenum disul?de,immunosensor
更新于2025-09-04 15:30:14
-
Dual-Channel Photoelectrochemical Ratiometric Aptasensor with Up-converting Nanocrystals Using Spatial-Resolved Technique on Homemade 3D Printed Device
摘要： A near-infrared light (NIRL)-activated ratiometric photoelectrochemical (PEC) aptasensor was fabricated for detection of carcinoembryonic antigen (CEA) coupling with upconversion nanoparticles (UCNPs)-semiconductor nanocrystals-based spatial-resolved technique on a homemade 3D printing device in which a self-regulating integrated electrode was designed for dual signal readout. The as-prepared NaYF4:Yb, Er UCNPs@CdTe nanocrystals were initially assembled on two adjacent photoelectrodes, then CEA aptamer 1 (A1) and capture DNA (CA) were modified onto two working photoelectrodes (WP1 and WP2) through covalent binding, respectively, and then gold nanoparticle-labeled CEA aptamer 2 (Au NP-A2) were immobilized on the surface of functional WP2 for the formation of double-stranded DNA. Upon target CEA introduction, the various concentrations of CEA were captured on the WP1, whereas the binding of the CEA with Au NP-A2 could be released from the WP2 thanks to the highly affinity of CEA toward A2. The dual signal readout with the 'signal-off' of WP1 and 'signal-on' of WP2 were employed for the spatial-resolved PEC (SR-PEC) strategy to detect CEA as an analytical model. Combining NaYF4:Yb, Er UCNPs@CdTe nanocrystals with spatial-resolved model on 3D printing device, the PEC ratiometric aptasensor based on steric hindrance effect and exciton-plasmon interactions (EPI) exhibited a linear range from 10.0 pg mL-1 to 5.0 ng mL-1 with a limit of detection of 4.8 pg mL-1 under 980 nm illumination. The SR-PEC ratiometric strategy showed acceptable stability and reproducibility with a superior anti-interference ability. This approach can provide the guidance for the design of ratiometric, multiplexed and point-of-care biosensors.
关键词： 3D printing device,upconversion nanoparticles,Photoelectrochemical biosensor,ratiometric,spatial-resolved technique,carcinoembryonic antigen
更新于2025-09-04 15:30:14