Graphdiyne chelated AuNPs for ultrasensitive electrochemical detection of tyrosine.

Tyrosine (Tyr) is a kind of amino acid that can regulate emotions and stimulate the nervous system, and it is of great importance to realize its ultrasensitive detection. A unique material of graphdiyne chelated AuNPs (GDY@AuNPs) is designed and developed to realize high-performance electrochemical sensing of Tyr. GDY promotes the absorption of Tyr π-π interaction, and its CC strongly chelates with AuNPs for greatly improved sensitivity.

Directionally In Situ Self-Assembled, High-Density, Macropore-Oriented, CoP-Impregnated, 3D Hierarchical Porous Carbon Sheet Nanostructure for Superior Electrocatalysis in the Hydrogen Evolution Reaction.

3D ZIF-67-particles-impregnated cellulose-nanofiber nanosheets with oriented macropores are synthesized via directional-freezing-assisted in situ self-assembly, and converted to 3D CoP-nanoparticle (NP)-embedded hierarchical, but macropores-oriented, N-doped carbon nanosheets via calcination and phosphidation. The obtained nanoarchitecture delivers overpotentials at 10 and 50 mA cm and Tafel slope of 82.1 and 113.

A high-energy-state biomimetic enzyme of oxygen-deficient MnTiO nanodiscs for sensitive electrochemical sensing of the superoxide anion.

It is of great importance to determine the superoxide anion (O2˙-), a kind of active free radical that plays important roles in catalytic and biological processes. We present here a high-energy-state biomimetic enzyme with extraordinary activity for O2˙- by inducing surface oxygen defects in MnTiO3 nanodiscs. Oxygen defects enable surface rich active Mn sites with high oxidation ability, which significantly promote the adsorption and electro-oxidation of O2˙-.

Room temperature-formed iron-doped nickel hydroxide on nickel foam as a 3D electrode for low polarized and high-current-density oxygen evolution.

Unique room temperature-formed iron-doped nickel hydroxide on Ni foam as a 3D electrode in alkaline electrolyte offers fast gas dissipation, a high number of active sites and a high oxidation state of Ni for an improved oxidation ability for the oxygen evolution reaction (OER), which delivers an OER current density of 100 mA cm-2 at an overpotential of 0.312 V and 96.3% retention after 100 h at an overpotential of 0.

Au@CdS Core-Shell Nanoparticles-Modified ZnO Nanowires Photoanode for Efficient Photoelectrochemical Water Splitting.

Hydrogen production from water splitting using solar energy based on photoelectrochemical (PEC) cells has attracted increasing attention because it leaves less of a carbon footprint and has economic superiority of solar and hydrogen energy. Oxide semiconductors such as ZnO possessing high stability against photocorrosion in hole scavenger systems have been widely used to build photoanodes of PEC cells but under visible light their conversion efficiencies with respect to incident-photon-to-current conversion efficiency (IPCE) measured without external bias are still not satisfied. An innovative way is presented here to significantly improve the conversion efficiency of PEC cells by constructing a core-shell structure-based photoanode comprising Au@CdS core-shell nanoparticles on ZnO nanowires (Au@CdS-ZnO).

Nitrogen doped carbon nanoparticles enhanced extracellular electron transfer for high-performance microbial fuel cells anode.

Nitrogen doped carbon nanoparticles (NDCN) were applied to modify the carbon cloth anodes of microbial fuel cells (MFCs) inoculated with Shewanella oneidensis MR-1, one of the most well-studied exoelectrogens. Experimental results demonstrated that the use of NDCN increased anodic absorption of flavins (i.e.

One-pot synthesis of CO₂-responsive magnetic nanoparticles with switchable hydrophilicity.

CO2-responsive nanoparticles have been attracted increasing interest due to their benign reactions with CO2 that give them gas-switchable properties, which can be easily reversed by mild heating or purging with inert gases. In this work, we have prepared CO2-responsive magnetic nanoparticles in a simple one-pot polyol synthesis using diaminoalkanes as the surfactant. The as-synthesized nanoparticles show excellent reversible aggregation and dispersion in response to alternating purging of N2 and CO2 at room temperature.

Ethylenediamine-mediated synthesis of Mn₃O₄ nano-octahedrons and their performance as electrocatalysts for the oxygen evolution reaction.

Mn₃O₄ octahedrons with well-defined facets exhibit enhanced catalytic activity and sensing characteristics, and have attracted considerable attention in recent years. However, current fabrication methods for Mn₃O₄ octahedrons generally produce particles of micron and sub-micron sizes, and impurities such as MnO₂ and Mn₂O₃ are often found. We present the synthesis of Mn₃O₄ nano-octahedrons with a pure Mn₃O₄ phase and size down to 50 nm based on a hydrothermal method using Mn(NO₃)₂ as the manganese source and ethylenediamine (EDA) as the structure-mediating agent.

Na⁺-functionalized carbon quantum dots: a new draw solute in forward osmosis for seawater desalination.

A new type of biocompatible draw solute, Na(+)-functionalized carbon quantum dots (Na_CQDs) with ultra-small size and rich ionic species, in forward osmosis (FO) is developed for seawater desalination. The aqueous dispersion of Na_CQDs demonstrates a high osmotic pressure, which allows high FO water flux and negligible reverse solute permeation.

DNA-assisted assembly of carbon nanotubes and MnO2 nanospheres as electrodes for high-performance asymmetric supercapacitors.

A DNA-assisted assembly approach is developed to fabricate a capacitor-type electrode material, DNA-functionalized carbon nanotubes (CNTs@DNA), and a battery-type electrode material, DNA@CNTs-bridged MnO2 spheres (CNTs@DNA-MnO2), for asymmetric supercapacitors. An energy density of 11.6 W h kg(-1) is achieved at a power density of 185.

Graphene oxide-enabled tandem signal amplification for sensitive SPRi immunoassay in serum.

A tandem signal amplification using bioconjugated graphene oxide and subsequent silver catalytic deposition for surface plasmon resonance imaging (SPRi) to sensitively and specifically immunoassay tumor biomarkers in serum, achieving a limit of detection down to 100 pg mL(-1) with a broad dynamic range for α-Fetoprotein (AFP) is reported.

A new class of fluorescent-dots: long luminescent lifetime bio-dots self-assembled from DNA at low temperatures.

Quantum-dots (QDs) have fuelled up intensive research efforts over the past two decades. Nevertheless, currently developed two classes of fluorescent QDs, colloidal semiconductor QDs and carbonaceous QDs suffer from either toxicity or short luminescence lifetime. Here, we report a new class of fluorescent bio-dots that are derived from DNA via self-assembly at low temperatures down to 80°C, which has an optical bandgap of 3.

Graphene quantum-dot-doped polypyrrole counter electrode for high-performance dye-sensitized solar cells.

Herein graphene quantum dot (GQD), a graphene material with lateral dimension less than 100 nm, is explored to dope PPy on F-doped tin oxide glass as an efficient counter electrode for high-performance dye-sensitized solar cells (DSSCs). The GQDs-doped PPy film has a porous structure in comparison to the densely structured plain PPy, and displays higher catalytic current density and lower charge transfer resistance than the latter toward I3(-)/I(-) redox reaction. The highest power conversion efficiency (5.

Template-free bottom-up synthesis of yolk-shell vanadium oxide as high performance cathode for lithium ion batteries.

A template-free strategy is exploited to bottom-up synthesize yolk-shell vanadium oxide through a two-step spontaneous assembly of hydrolytically formed subunits in a one-pot process. The unique structured vanadium pentoxide exhibits excellent cathode performance for lithium ion batteries.

Functionalization of SnO₂ photoanode through Mg-doping and TiO₂-coating to synergically boost dye-sensitized solar cell performance.

Mg-doped SnO₂ with an ultrathin TiO₂ coating layer was successfully synthesized through a facile nanoengineering art. Mg-doping and TiO₂-coating constructed functionally multi-interfaced SnO₂ photoanode for blocking charge recombination and enhancing charge transfer in dye-sensitized solar cells (DSC). The designed nanostructure might play a synergistic effect on the reducing recombination and prolonging the lifetime in DSC device.

DNA-directed growth of Pd nanocrystals on carbon nanotubes towards efficient oxygen reduction reactions.

Unique DNA-promoted Pd nanocrystals on carbon nanotubes (Pd/DNA-CNTs) are synthesized for the first time, in which through its regularly arranged PO(4)(3-) groups on the sugar-phosphate backbone, DNA directs the growth of ultrasmall Pd nanocrytals with an average size of 3.4 nm uniformly distributed on CNTs. The Pd/DNA-CNT catalyst shows much more efficient electrocatalytic activity towards oxygen reduction reaction (ORR) with a much more positive onset potential, higher catalytic current density and better stability than other Pd-based catalysts including Pd nanocrystals on carbon nanotubes (Pd/CNTs) without the use of DNA and commercial Pd/C catalyst.

In situ synthesized heteropoly acid/polyaniline/graphene nanocomposites to simultaneously boost both double layer- and pseudo-capacitance for supercapacitors.

It is challenging to simultaneously increase double layer- and pseudo-capacitance for supercapacitors. Phosphomolybdic acid/polyaniline/graphene nanocomposites (PMo(12)-PANI/GS) were prepared by using PMo(12) as a bifunctional reagent for not only well dispersing graphene for high electrochemical double layer capacitance but also in situ chemically polymerizing aniline for high pseudocapacitance, resulting in a specific capacitance of 587 F g(-1), which is ~1.5 and 6 times higher than that of PANI/GS (392 F g(-1)) and GS (103 F g(-1)), respectively.

Nanoparticle self-assembled hollow TiO2 spheres with well matching visible light scattering for high performance dye-sensitized solar cells.

Submicrometer-sized hollow TiO(2) spheres are directly self-assembled from TiO(2) nanoparticles without using any template or surfactant as a scattering layer for dye-sensitized solar cells, showing good visible light scattering match to significantly improve the photoconversion efficiency.

RGD-peptide functionalized graphene biomimetic live-cell sensor for real-time detection of nitric oxide molecules.

It is always challenging to construct a smart functional nanostructure with specific physicochemical properties to real time detect biointeresting molecules released from live-cells. We report here a new approach to build a free-standing biomimetic sensor by covalently bonding RGD-peptide on the surface of pyrenebutyric acid functionalized graphene film. The resulted graphene biofilm sensor comprises a well-packed layered nanostructure, in which the RGD-peptide component provides desired biomimetic properties for superior human cell attachment and growth on the film surface to allow real-time detection of nitric oxide, an important signal yet short-life molecule released from the attached human endothelial cells under drug stimulations.

Microelectrodes with gold nanoparticles and self-assembled monolayers for in vivo recording of striatal dopamine.

Electrochemical determination of in vivo dopamine (DA) using implantable microelectrodes is essential for monitoring the DA depletion of an animal model of Parkinson's disease (PD), but faces substantial interference from ascorbic acid (AA) in the brain area due to similar electroactive characteristics. This study utilizes gold nanoparticles (Au-NPs) and self-assembled monolayers (SAMs) to modify platinum microelectrodes for improving sensitivity and specificity to DA and alleviating AA interference. With appropriate choice of ω-mercaptoalkane carboxylic acid chain length, our results show that a platinum microelectrode coated with Au-NPs and 3-mercaptopropionic acid (MPA) has approximately an 881-fold specificity to AA.

Graphene/carbon cloth anode for high-performance mediatorless microbial fuel cells.

Graphene was electrochemically deposited on carbon cloth to fabricate an anode for a Pseudomonas aeruginosa mediatorless microbial fuel cell (MFC). The graphene modification improved power density and energy conversion efficiency by 2.7 and 3 times, respectively.

All-printed carbon nanotube finFETs on plastic substrates for high-performance flexible electronics.

The performance of all-printed flexible electronics is still much lower than silicon devices and significantly limits their commercially viable production. All-printed flexible carbon nanotube (CNT) fin field-effect transistors (FETs) with dielectric-wrapped CNT network are demonstrated with remarkable performance, making it possible to mass-produce high-performance, all-printed flexible electronics on large-area substrates.

Sensitive protein microarray synergistically amplified by polymer brush-enhanced immobilizations of both probe and reporter.

Great challenge remains to continuously improve sensitivity of protein microarrays for broad applications. A copolymer brush is in situ synthesized on both substrate and silica nanoparticle (SNP) surface to efficiently immobilize probe and reporter protein respectively for synergistic amplification of protein microarray signals. As a demonstration, sandwich immunoassay for a cancer biomarker carcinoembryonic antigen (CEA) detection is performed on microarray platform, showing a limit of detection (LOD) of 10 pg/ml and dynamic range of 10 pg/ml to 100 ng/ml.

CeO2 nanoparticles/graphene nanocomposite-based high performance supercapacitor.

CeO(2) nanoparticles/graphene nanocomposite is fabricated by depositing CeO(2) nanoparticles onto three-dimensional graphene material and its supercapacitor performance is further investigated. The nanocomposite shows a high specific capacitance and power density, demonstrating a strong synergistic effect possibly contributed from improved conductivity of CeO(2) and better utilization of graphene.

Reduction of charge recombination by an amorphous titanium oxide interlayer in layered graphene/quantum dots photochemical cells.

The effect of an amorphous TiO(x) interlayer on layered graphene/quantum dots photochemical cells has been investigated. The addition of the TiO(x) interlayer eliminates the decay of photocurrent in the initial seconds after light illumination and significantly increases the slope of the steady-state photocurrent versus the light intensity. The open-circuit voltage decay measurements further illustrate a longer electron lifetime when an amorphous TiO(x) interlayer is applied.