Electrochemical dopamine sensor based on bi-metallic Co/Zn porphyrin metal-organic framework.

Integrating other metal ions into mono-metallic metal-organic framework (MOF) to form bi-metallic MOF is an effective strategy to enhance the performance of MOFs from the internal structure. In this study, two-dimensional (2D) cobalt/zinc-porphyrin (Co/Zn-TCPP) MOF nanomaterials with different Co/Zn molar ratios were synthesised using a simple surfactant-assisted method, and novel dopamine (DA) sensing methods were constructed based on these materials. The characterisation results showed that all MOF with different Co/Zn molar ratios presented a nanofilm, and the Co and Zn elements were uniformly distributed.

A novel self-cleaning electrochemical biosensor integrating copper porphyrin-derived metal-organic framework nanofilms, G-quadruplex, and DNA nanomotors for achieving cyclic detection of lead ions.

A self-cleaning electrochemical biosensor based on two-dimensional Cu-porphyrin (Cu-TCPP) metal-organic framework nanofilms, novel super G-quadruplex (G4), and DNA nanomotors was developed for the cyclic detection of Pb ions. The Cu-TCPP framework with inherent peroxidase activity can create an ultra-thin nanofilm that functioned as a carrier to support the metastable G4 comprising four individual DNA strands. The introduction of Pb and the intercalation of hemin can help it to form stable G4-hemin DNAzymes, which exhibits strong catalytic HO reduction activity, and its number will be directly related to the amount of the introduced Pb.

Fluorescence and electrochemical assay for bimodal detection of lead ions based on Metal-Organic framework nanosheets.

The accurate measurement of heavy metal ions is essential for human health and environmental protection. Here, we report the design of a simple and convenient bimodal strategy for signal-on, label-free lead ion detection in environmental samples based on two-dimensional metal-organic framework (2D-MOF) nanosheets. 2D-MOFs have different affinities toward guanine-rich DNA (ssGDNA) and the G-quadruplex, allowing these structures to be distinguished.

Amplified Electrochemical Hydrogen Peroxide Sensing Based on Cu-Porphyrin Metal-Organic Framework Nanofilm and G-Quadruplex-Hemin DNAzyme.

A novel electrochemical hydrogen peroxide (HO) sensor based on Cu-porphyrin(Cu-TCPP)/G-quadruplex-hemin nanocomposite was constructed by assembling two-dimensional Cu-TCPP metal-organic framework (MOF) nanofilm and G-quadruplex-hemin DNAzyme. The Cu-TCPP synthesized by the surfactant-assisted method has a wrinkled two-dimensional nanofilm morphology, which gives it a large surface area and accessible active sites. Cu-TCPP exhibits peroxidase activity and good stability and can catalyze the reduction of HO.

Non-enzymatic electrochemical hydrogen peroxide sensing using a nanocomposite prepared from silver nanoparticles and copper (II)-porphyrin derived metal-organic framework nanosheets.

A non-enzymatic hydrogen peroxide (HO) electrochemical sensor material was prepared from silver nanoparticles and a 2D copper-porphyrin framework (MOF). The structure and morphology of the nanocomposite were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results showed that the MOF has a two-dimensional sheet structure, and a large number of Ag NPs are uniformly attached to it.

Direct growth of ordered PdCu and Co doped PdCu nanoparticles on graphene oxide based on a one-step hydrothermal method for ultrasensitive sensing of HO in living cells.

Ordered PdCu and Co doped PdCu nanoparticles have been synthesized on graphene oxide (GO). The obtained Co-PdCu/GO composites were used to fabricate a H2O2 electrochemical sensor which exhibits an ultralow LOD (limit of detection) of 1.2 nM and an extra broad linear range of 5 nM-5.

Preparation of high-quality palladium nanocubes heavily deposited on nitrogen-doped graphene nanocomposites and their application for enhanced electrochemical sensing.

A nanocomposite of high-quality palladium nanocubes (PdNCs) decorated nitrogen-doped graphene (NGE/PdNC) was successfully prepared by using bromide ion as a capping agent and polyvinyl pyrrolidone as a stabilizer. The morphology and composition of NGE/PdNC nanocomposites were characterized by field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and Raman spectra. To explore the application of NGE/PdNC nanocomposites in electrochemistry, the electrocatalytic response to nitrite at a NGE/PdNC-based electrode was investigated.

Morphology controlled synthesis of platinum nanoparticles performed on the surface of graphene oxide using a gas-liquid interfacial reaction and its application for high-performance electrochemical sensing.

In this paper, we report a novel morphology-controlled synthetic method. Platinum (Pt) nanoparticles with three kinds of morphology (aggregation-like, cube-like and globular) were grown on the surface of graphene oxide (GO) using a simple gas-liquid interfacial reaction and Pt/GO nanocomposites were obtained successfully. According to the experimental results, the morphology of the Pt nanoparticles can be controlled by adjusting the reaction temperature with the protection of chitosan.

Hydrophobic interface controlled electrochemical sensing of nitrite based on one step synthesis of polyhedral oligomeric silsesquioxane/reduced graphene oxide nanocomposite.

In this paper, we report a novel hydrophobic interface controlled electrochemical sensing of nitrite based on polyhedral oligomeric silsesquioxane/ reduced graphene oxide nanocomposite (POSS/rGO). The POSS/rGO is prepared by one step hydrothermal synthesis method, and characterized by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR), Zeta-potential measurement analyzer, electrochemical impedance spectroscopy (EIS) and zero current potential method respectively. Then the POSS/rGO composite is used to fabricate electrochemical sensor for nitrite detection.

Layer-by-layer assembly of copper nanoparticles and manganese dioxide-multiwalled carbon nanotubes film: A new nonenzymatic electrochemical sensor for glucose.

A nonenzymatic glucose sensor based on Cu/MnO2/MWCNTs nanocomposite modified glass carbon electrode was fabricated by an electrochemical method. Transmission electron microscopic (TEM) measurement showed that MnO2 in the nanocomposite held a nanostructure of three-dimension (3D) spheres assembled by many densely arranged nanosheets. The electrocatalytic activity of the present sensor toward the oxidation of glucose was investigated by amperometry.

Controllable Synthesis of Formaldehyde Modified Manganese Oxide Based on Gas-Liquid Interfacial Reaction and Its Application of Electrochemical Sensing.

Controllable synthesis of manganese oxides was performed via a simple one-step synthetic method. Then obtained manganese oxides which exhibit flower-like, cloud-like, hexagon-like, and rod-like morphologies were modified by formaldehyde based on a simple self-made gas-liquid reaction device respectively and the modified manganese oxides with coral-like, scallop-like and rod-like morphology were synthesized accordingly. The obtained materials were characterized and the formation mechanism was also researched.

Ultrasensitive electrochemical detection of breast cancer cells based on DNA-rolling-circle-amplification-directed enzyme-catalyzed polymerization.

An ultrasensitive cytosensor based on DNA-rolling-circle-amplification-directed enzyme-catalyzed polymerization is demonstrated. As a proof of concept, the cytosensor shows excellent sensitivity for MCF-7 cell detection with a lower detection limit of 12 cells per mL.

Novel silver nanoparticle-manganese oxyhydroxide-graphene oxide nanocomposite prepared by modified silver mirror reaction and its application for electrochemical sensing.

A gas/liquid interface will be formed when the free volatilized methyl aldehyde gas begins to dissolve in to solution. On the basis of the traditional silver mirror reaction, silver nanoparticle-manganese oxyhydroxide-graphene oxide (Ag-MnOOH-GO) nanocomposite was synthesized at the gas/liquid interface without any protection of inert gas at room temprature. The morphology of the nanocomposites could be controlled by adjusting the reaction temperature and time.