Sun Zhuo,Lu Juan,Zhang Xin,Shan Xiangyu,Wu Qian,Li Chao,Li Huiling,Yang Shuning,Tian Li
Electrospun nanofibers containing CdTe@ZnNi-metal–organic frameworks (CdTe@ZnNi-MOF NFs) were used for the first time in luminol-O 2 electrochemiluminescence (ECL) system to construct ECL sensor for chlorpyrifos (CPF) detection. Firstly, CdTe@ZnNi-MOF NFs obtained by blending method was used to modify the surface of a glassy carbon electrode, and then, the proposed solid-state ECL sensor was constructed by dropping luminol onto the surface of nanofiber benefiting from chitosan (CTS) viscosity. CdTe@ZnNi-MOF NFs with its large surface area and porosity can be used not only as luminol carrier but also as co-reaction promoter of the ECL system. The ECL sensor obtained satisfactory results in weakly alkaline solution under the synergistic action of CdTe@ZnNi-MOF NFs and luminol. The constructed ECL sensor can effectively detect CPF in the range 1.0 × 10 −14 –1.0 × 10 −9 M, and the detection limit was 6.23 × 10 −17 M (3 σ / m ). The constructed sensor was simple and sensitive, and can be used for the determination of CPF in vegetable samples. It not only broadened the application of MOFs in the field of ECL but also provided a new idea for expanding the application of the luminol-O 2 system. Graphical Abstract
Improvement in the sensitivity and accuracy of ECL-based biosensors, to a great extent, depends on the fabrication of high-performance electrochemiluminescence (ECL) sensors. Herein, polyethyleneimine (PEI)-grafted bimetallic ZnNi metal-organic framework (ZnNi-MOF/PEI) nanospheres were synthesized to prepare a L012-based ECL immunosensor for detecting carbohydrate antigen 15-3 (CA15-3). The introduced PEI was utilized not only as a bridging element for L012 luminophore and detection antibody (Ab 2 ) immobilization but also as a co-reactant for generating the self-enhanced ZnNi-MOF/PEI-L012@Ab 2 ECL signal probe. Furthermore, Pt nanoparticle-functionalized CeO 2 nanorods (CeO 2 -Pt) featuring high-efficiency electrocatalytic properties, as a co-reaction accelerator, could catalyze H 2 O 2 to generate abundant reactive oxygen species (ROS), further augmenting the ECL signal of ZnNi-MOF/PEI-L012@Ab 2 . In the presence of CA15-3 antigen, the capture antibody (Ab 1 )-conjugated CeO 2 -Pt complex (CeO 2 -Pt@Ab 1 ) and ZnNi-MOF/PEI-L012@Ab 2 would get closer to each other, with the formation of a "signal-on" sandwich-type ECL immunosensor. The ZnNi-MOF-assisted ECL biosensor achieved a detection limit of down to 5.75✕10 -5 U mL -1 . This work shows distinguished potential for measuring low levels of biomarkers that may help in the clinical diagnosis of breast cancer.
Linyuan Zhai,Xinyi Feng,Huali Jin,Tian Bai,Min Wei,Yong Liu,Zhiguang Suo
Cadmium ions (Cd 2+ ) as a class of widespread pollutants, can cause Irreversible damage to population health and habitat quality with small amounts of Cd 2+ . an electrochemical sensor for Cd 2+ detection was developed based on AuPt NPs@ZnNi-MOF bimetallic nanocomposites combined with hyperbranched hybridization chain reaction (HCR) signal amplification strategies. The sensor employed AuPt NPs@ZnNi-MOF as the electrode modification material, which promoted the electron transport on the electrode surface and significantly increased the current signal by 49.16 %, as well as provided a large number of active sites for the sensor. 3D DNA walker was initiated in the presence of the target, generating many DNA single strands that triggered catalytic hairpin self-assembly (CHA) at the electrode. The production of intermediate strand output is induced, which leads to the construction of hyperbranched HCR. Hyperbranched HCR amplification demonstrated high efficiency, producing numerous long double-stranded chains and creating abundant embedding sites for electroactive molecules. These signal amplification strategies led to a remarkable 2.52-fold enhancement in the current signal. Under the optimal experimental conditions, the detection range of the sensor was 0.001–500 nmol/L, and the limit of detection (LOD) was 0.221 pmol/L. Furthermore, the sensor exhibits excellent specificity, reproducibility, and stability, and has been successfully applied for the detection of Cd 2+ in tap water and tea, as well as achieving satisfactory results in the analysis of quality control samples such as rice flour and pork liver powder.
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