Interfacial superassembly of flower-like NiMn-LDH@poly-l-lysine composites for selective electrochemical sensing of tryptophan.

Development of sensitive, selective, and facile electrochemical analytical approaches to monitor tryptophan in different samples is of high significance. For such approaches, efficient electrodes play the key role. Herein, a NiMn-layered double hydroxide (LDH)@poly-l-lysine (PLL) composite has been prepared through in-situ electro-polymerization and further utilized to monitor tryptophan in medicament and biological systems.

Coupling W O /Ti C T MXene Pseudocapacitive Electrodes with Redox Electrolytes to Construct High-Performance Asymmetric Supercapacitors.

A pseudocapacitive electrode with a large surface area is critical for the construction of a high-performance supercapacitor. A 3D and interconnected network composed of W O nanoflowers and Ti C T MXene nanosheets is thus synthesized using an electrostatic attraction strategy. This composite effectively prevents the restacking of Ti C T MXene nanosheets and meanwhile sufficiently exposes electrochemically active sites of W O nanoflowers.

Morphology-dependent sensing performance of CuO nanomaterials.

The morphology of nanomaterials affects their properties and further their applications. Herein, CuO nanomaterials with different morphologies are synthesized, including CuO nanostrips, nanowires and microspheres. After their characterization by means of electron microscopy and X-ray powder diffraction, these CuO nanomaterials are further mixed with graphene nanoplates (GNP) to explore their performance towards electrochemical detection of glucose and tetrabromobisphenol A (TBBPA).

A UiO-66-NH/carbon nanotube nanocomposite for simultaneous sensing of dopamine and acetaminophen.

Carbon nanomaterials are quite promising to be combined with metal-organic frameworks (MOFs) to enhance the sensing ability of both materials. In this work, a MOF nanoparticle of UiO-66-NH is integrated with carbon nanotubes (CNTs) (UiO-66-NH/CNTs) with a facile solvothermal method. The morphology, surface area and properties of this UiO-66-NH/CNTs nanocomposite was investigated using electron microscopy, XRD, XPS, BET analysis and electrochemical techniques.

Morphology-controlled electrochemical sensing of environmental Cd and Pb ions on expanded graphite supported CeO nanomaterials.

Heavy metal ions (e.g., Cd and Pb) are widely existed in environment and highly toxic.

Tailoring the CeO morphology and its electrochemical reactivity for highly sensitive and selective determination of dopamine and epinephrine.

Four CeO nanomaterials with the morphologies of a nanoplate (CeO-p), a nanocube (CeO-c), a porous triangular microplate (CeO-t), and of a porous hierarchical rod-stacked nanobundle (CeO-b) were synthesized using a hydrothermal method. They were characterized by scanning and transmission electron microscopies, X-ray diffraction and X-ray photoelectron spectroscopy. Electrochemical characterizations reveal the tuning of their morphology and the presence of exposed crystal planes of CeO that can be realized by changing the alkali sources.

Recent Advances of Porous Graphene: Synthesis, Functionalization, and Electrochemical Applications.

Graphene is a 2D sheet of sp bonded carbon atoms and tends to aggregate together, due to the strong π-π stacking and van der Waals attraction between different layers. Its unique properties such as a high specific surface area and a fast mass transport rate are severely blocked. To address these issues, various kinds of 2D holey graphene and 3D porous graphene are either self-assembled from graphene layers or fabricated using graphene related materials such as graphene oxide and reduced graphene oxide.

Graphene nanoplatelet supported CeO nanocomposites towards electrocatalytic oxidation of multiple phenolic pollutants.

To explore suitable sensing materials for sensitive and selective detection of phenolic pollutants, CeO nanocubes, nanopolyhedras, and nanorods were synthesized by a hydrothermal method. These CeO nanomaterials were further loaded on the support of graphene nanoplatelets. As-synthesized nanomaterials and nanocomposites were characterized using transmission electron microscopy, X-ray diffraction and Raman spectroscopy as well as electrochemical techniques including cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry.

Three-dimensional catalyst systems from expanded graphite and metal nanoparticles for electrocatalytic oxidation of liquid fuels.

Cheap and high-performance electrocatalysts are required for fuel cells. Herein, we present the application of three-dimensional (3D) catalyst systems for electrocatalytic oxidation of formic acid and methanol. These systems consist of cost-effective boron-doped expanded graphite (B-EG) as the support and palladium nanoparticles (NPs) or platinum/palladium bimetal NPs as the catalysts.

Electrochemical Grafting of Graphene Nano Platelets with Aryl Diazonium Salts.

To vary interfacial properties, electrochemical grafting of graphene nano platelets (GNP) with 3,5-dichlorophenyl diazonium tetrafluoroborate (aryl-Cl) and 4-nitrobenzene diazonium tetrafluoroborate (aryl-NO) was realized in a potentiodynamic mode. The covalently bonded aryl layers on GNP were characterized using atomic force microscopy and X-ray photoelectron spectroscopy. Electrochemical conversion of aryl-NO into aryl-NH was conducted.

High-Performance Electrochemical Catalysts Based on Three-Dimensional Porous Architecture with Conductive Interconnected Networks.

The electrochemical applications of traditional carbon nanomaterials such as carbon nanotubes (CNTs) and graphene (G) powders are significantly impeded by their poor three-dimensional (3D) conductivity and lack of hierarchical porous structure. Here, we have constructed a 3D highly conductive CNTs networks and further combined it with mesoporous carbon (mC) for the creation of a core-shell structured (CNT@mC) composite sponge that featured 3D conductivity and hierarchical porous structure. In the composite sponge, interconnected CNTs efficiently eliminates the contact resistance and the hierarchical pores significantly facilitate the mass transport.

Universal electrode interface for electrocatalytic oxidation of liquid fuels.

Electrocatalytic oxidations of liquid fuels from alcohols, carboxylic acids, and aldehydes were realized on a universal electrode interface. Such an interface was fabricated using carbon nanotubes (CNTs) as the catalyst support and palladium nanoparticles (Pd NPs) as the electrocatalysts. The Pd NPs/CNTs nanocomposite was synthesized using the ethylene glycol reduction method.

Versatile matrix for constructing enzyme-based biosensors.

A versatile matrix was fabricated and utilized as a universal interface for the construction of enzyme-based biosensors. This matrix was formed on the gold electrode via combining self-assembled monolayer of 2,3-dimercaptosuccinic acid with gold nanoparticles. Gold nanoparticles were electrochemically deposited.

Graphene nanoplatelets: electrochemical properties and applications for oxidation of endocrine-disrupting chemicals.

In most graphene-based electrochemical applications, graphene nanoplatelets (GNPs) have been applied. Now, for the first time, electrochemical properties of GNPs, namely, its electrochemical activity, potential window, and double-layer capacitance, have been investigated. These properties are compared with those of carbon nanotubes (CNTs).

In situ synthesized gold nanoparticles for direct electrochemistry of horseradish peroxidase.

In order to construct a three-dimensional electrode, in situ electrochemical deposition of gold nanoparticles onto a gold electrode coated with a self-assembled monolayer of 3-mercaptopropionic acid (Au NP/MPA/Au) was conducted. Horseradish peroxidase (HRP) was then immobilized into this three-dimensional electrode, leading to the realization of direct electron transfer of HRP. Scanning electron microscopy and electrochemical impedance spectroscopy were applied to characterize the electrode before and after HRP immobilization.

Bucky-gel coated glassy carbon electrodes, for voltammetric detection of femtomolar leveled lead ions.

Femtomolar (fM) leveled lead ions were electrochemically detected using a bucky-gel coated glassy carbon electrode and differential pulse anodic stripping voltammetry. The bucky-gel was composed of dithizone, ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate), and multi-walled carbon nanotubes (MWCNTs). The fabrication of the bucky-gel coated electrode was optimized.

Voltammetric determination of mercury (II) in aqueous media using glassy carbon electrodes modified with novel calix[4]arene.

A novel calix[4]arene derivative containing benzothiazole group was coated on glassy carbon electrode (GCE) and then applied to the recognition of mercury ion. Cyclic and square wave voltammetric results showed that the modified electrode selectively recognizes Hg(2+) ion in aqueous media. A new anodic stripping peak at -0.

Electrochemical behavior of thiamine on a self-assembled gold electrode and its square-wave voltammetric determination in pharmaceutical preparations.

The electrochemical behavior of thiamine on a self-assembled electrode of L-cysteine (Cys/SAM/Au) has been investigated and Cys/SAM/Au can be used to detect thiamine using square-wave voltammetry (SWV). At pH 11.40 Britton-Robinson buffer, thiamine exhibits a well-defined anodic peak on Cys/SAM/Au.