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A W-doped Pt modified graphene oxide (Pt-W-GO) electrochemical microelectrode was developed to detect hydrogen peroxide (H 2 O 2 ) in real time at a subcellular scale. Interestingly, results showed that the concentration of H 2 O 2 in the nucleus of HeLa cells was 2.68 times and 0.51 times that in the extracellular membrane and cytoplasm, respectively.

A twice-walk strategy based on a three-dimensional (3D) cleat-equipped DNA walking machine with a high signal amplification efficiency was investigated for ultrasensitive detection of miRNA. Impressively, addition of duplex-specific nuclease (DSN) just once drove the twice-walk strategy, making the strategy simpler. With the advantages of being simple, rapid and ultrasensitive, the biosensor offers potential for use in early clinical diagnosis.

ZnO-Au@ZIF-8 core-shell heterostructures were prepared by ZIF-8 encapsulation of sacrificial ZnO-Au nanorods. Because of the catalytic activity of the Au nanoparticles and the sieving effects of the ZIF-8, the ZnO-Au@ZIF-8 heterostructures showed an outstanding response of 1.8 to 5 ppb NO 2 , and exhibited higher selectivity, stability, anti-humidity and fast response and recovery properties. The combination of the gas-selective catalytic activity of noble metals with the MOF filter used in this work can be easily extended to synthesize other types of MOS@MOF sensors, opening a new avenue for the detection of hazardous gases.

Phosphorene nanoribbons (PNRs) combine the flexibility of one-dimensional (1D) nanomaterials with the large specific surface area and the edge and electron confinement effects of two-dimensional (2D) nanomaterials. In spite of the substantial advances in bulk black phosphorus (BP) manufacturing, achieving PNRs without degradation is still a big challenge. In this work, we present a strategy for the space-confined chemical vapor transport synthesis of quasi-one-dimensional surface-passivated monocrystalline PNRs on a silicon substrate. The growth mechanism of the PNRs is proposed by combining experimental results and DFT calculations, indicating that the P 4 molecules can break, restructure, and epitaxially nucleate on the surface of the Au 3 SnP 7 catalyst, and finally prefer to grow along the zigzag (ZZ) direction to form PNRs. The low gas flow rate and an appropriate phosphorus molecule concentration allow the growth of PNRs with structural integrity, which can be regulated by the amount of red phosphorus and the confined space.

Herein we report a 2D surface-coordinated porphyrinic metal-organic framework film (SURMOF) CuTCPP prepared by a layer by layer method as an optical limiting layer in a polymer-dispersed liquid crystal (PDLC) device. The results show that the CuTCPP SURMOF/PDLC device has excellent switchable transparency and optical limiting performance, providing a new route to achieve mutilfunctional electro-optical applications.

Herein, we illustrate how the cooperation of intermolecular hydrogen bonds and conformation flexibility leads to the formation of diverse complex covalent nanostructures on the surface, while the relative abundance of the final products can be further tuned by adjusting the molar ratio and concentration of monomers.

A novel strategy for the growth of molecularly thin two-dimensional molecular crystals (2DMCs) of organic semiconductors with poor solubility was developed. Large-area bilayer 2DMCs were grown on a liquid surface at elevated temperatures, with record mobility and superior photoresponse.

Herein, we designed and synthesized a precursor with a three-fold node and successfully constructed covalent Sierpiński triangle (ST) fractals with boronic ester linkages both at the liquid/solid interface at room temperature and by thermal annealing in a water atmosphere under ambient conditions. Remarkably, large-scale ordered superstructures of covalent STs are constructed by thermal annealing, which paves the way for property investigation of STs.

By the co-assembly of two carboxylic acids with distinct symmetries and different numbers of carboxyl groups, we obtained two novel cocrystal structures at the n-octanoic acid/HOPG interface, one of which was sustained by unoptimized R22(8) hydrogen bonding. Benefiting from the bias-sensitivity of the BTB (1,3,5-tris(4-carboxyphenyl)benzene) molecule, a structure transition between the cocrystal network and a denser BTB lamella is achieved.

Here, two large-area microporous polymer (MP) films with different substituents were synthesized at the solution/air interface. The on/off ratios of the MP-based memristors differ by an order of magnitude and the turn-on voltages differ by about 0.2 V, which is mainly attributed to the difference in band gap and pore environment of the materials.

An unconventional hydrothermal polycondensation of monomer salt crystals was readily performed to produce rectangular-shape amorphous polyimide submicrotubes, which show promising potentials in serving as both cathode and anode active materials for Li-ion batteries as well as being transformed into N-doped carbon tubes for supercapacitor electrodes.

We report a new biofunctionalized nanoplatform based on hyaluronic acid-coated gold-nano-dot-decorated hollow carbon nanospheres (AuHCNs-HA) for microRNA imaging in living cells. Importantly, the HA-coated nanoplatform could be internalized into target cells via CD44 receptor-mediated endocytosis. It can be further applied for intracellular miR-21 imaging in CD44-positive colorectal cancer cells.

Efficient access to evodiamine and its analogues is presented via Lewis acid catalysis. In this reaction, three chemical bonds and two heterocyclic-fused rings are constructed in one step. The reaction shows good functional group tolerance and atom economy, and various heteroatom-containing evodiamine analogues are obtained in moderate to excellent yields even on a gram scale. An anti-tumor study in vitro demonstrates compound 2b possesses potent efficacy against hepatoma cell line (IC50 = 5.7 μM).

The space-confined twin-polymerization of molecule-engineered silane monomers was performed to induce narrow large-micropores and/or small-mesopores into the oxygen-doped nanoporous carbons, capable of simultaneously achieving large specific capacitance and high rate capability for supercapacitors.

In this work we demonstrate that the surface adsorption and pH play a determining role in controlling the final product of a Schiff base reaction. Either 1D linear polymers or discrete macrocycles can be obtained by tuning the pH and surface confinement.

We investigate the effect of covalently modified graphitic surfaces on the formation of single-layer covalent organic frameworks (sCOFs) at the solid-liquid interface. The impact of different densities of grafted aryl species was tested on the on-surface synthesis of three distinct imine-based 2D sCOFs. The grafted aryl species that act as defects provide steric barriers to the progress of the Schiff-base reaction, and can be locally removed to start the 2D polymer healing process. This unique strategy provides a general approach to study in situ this dynamic covalent on-surface chemistry.

Hierarchical networks, constructed by non-covalent bond stabilized cross-junctions of covalent one-dimensional molecular wires, are synergistically formed at the liquid/solid interface through in situ on-surface condensation of aromatic amines and aldehydes. Our investigation demonstrates the significant impact of the concentration and structure of monomers on the hierarchical construction of these nanoarchitectures at the interface.

A two-dimensional covalent organic framework (2D COF), synthesized on a highly oriented pyrolytic graphite (HOPG) surface with benzene-1,3,5-tricarbaldehyde and p-phenylenediamine as the precursors, is used as a host to accommodate three guest molecules, coronene, copper phthalocyanine (CuPc), and fluorine-substituted copper phthalocyanine (F16CuPc). The host-guest interaction and dynamic behavior were investigated by scanning tunneling microscopy and density functional theory.

Though moderate heating in a controlled environment is generally considered to be necessary, in this work we show that the most important prerequisite for obtaining high quality 2D imine polymers at the interface is the concentration and molar ratio of building blocks on the surface. With diverse monomers we have demonstrated that the concentration-in-control strategy is a general and powerful way to construct covalent single layer 2D imine polymers with high regularity at the solid/liquid interface.

An imine-based 2D polymer side-functionalized with o-hydroxyl group was designed in regard to its potential ability to serve as a chelating agent and synthesized on a highly oriented pyrolytic graphite surface with a relatively low annealing temperature. When annealed to a higher temperature the o-hydroxyl group reacts further with the imine group, leading to the formation of oxazoline, which causes significant distortion to the network. The formation of oxazoline was further confirmed by ATR-FTIR.

We have designed and synthesized two porphyrin containing two-dimensional (2D) polymers based on the imine linkage. Both the 2D polymers are revealed to be 2D organic semiconductors with band gaps of around 1 eV. STM characterization reveals that the rigidity and affinity of building blocks to the surface has essential effects on the topology of the 2D polymers.

Using the widely available DMSO as the formylation reagent under oxidative conditions, an efficient Cu-catalyzed C3-formylation reaction of imidazo[1,2-a]pyridine C-H bonds to directly generate structurally sophisticated 3-formyl imidazo[1,2-a]pyridine derivatives has been developed. The reaction proceeded to generate products in good yields, and used the environmentally friendly molecular oxygen as the oxidant.

A highly efficient recognition phenomenon was observed between alkoxylated arylene-ethynylene macrocycles bearing identical side chains but different core size, which is based on van der Waals interactions between alkoxy chains. The ratio of both molecules and the environment of each molecule have been statistically analyzed to quantify the recognition efficiency.

Through the precise molecular design for alkoxy dehydro[12]annulene derivatives harnessed by a diacetylene unit in each alkyl chain, porous two-dimensional networks with giant pores were formed at the liquid/graphite interface.

On graphene grown on copper foil, oligothiophenes form identical supramolecular assemblies on different copper facets. Most importantly, we found that the graphene ripple structures, even with a height as small as ~0.5 nm, can significantly alter the molecule-substrate interaction, which has never been observed previously.

Copper phthalocyanine can assemble along PPE backbones into molecular arrays and 2D assemblies with structural parameters different from its intrinsic 2D crystal. The template effect depends on the match between the size of phthalocyanine and the repeating period of the PPE backbone., (This journal is © The Royal Society of Chemistry 2011)

We present for the first time a peculiar concentration effect on competitive adsorption of a binary mixture at the liquid/solid interface, which we attribute to the existence of pseudopolymorphism and its concentration dependence. These results are helpful for the understanding of phase behavior of multi-component systems at the interface.

At the liquid/graphite interface triangular and rhombic phenylene-ethynylene macrocycles substituted by alkyl chains self-assemble to form porous two-dimensional (2D) molecular networks of honeycomb and Kagomé types, respectively, or close-packed non-porous structures via alkyl chain interdigitation as the directional intermolecular linkages. Factors that affect the formation of the 2D molecular networks, such as alkyl chain length, solvent, solute concentration, and co-adsorption of guest molecules, were elucidated through a systematic study. For the porous networks, various molecules and molecular clusters were adsorbed in the pores reflecting the size and shape complementarity, exploring a new field of 2D host-guest chemistry.

SrAl(2)O(4):Eu(2+), Dy(3+) polynary complex nanotubes with long afterglow, templated by surfactant assemblies, were successfully synthesized by a homogeneous coprecipitation method, followed by heat treatment in a reducing atmosphere.

We present here the formation of giant pores in surface-confined molecular networks of a triangular-shaped dehydrobenzo-[12]annulene derivative: the diameter of the pores reaches over 7 nm and the giant pores are used as templates to accommodate a giant molecular spoked wheel, which allows us to observe rotational and adsorption-desorption dynamics of single guest molecules.

A monoalkylated tetrathiafulvalene derivative forms multilayer structures at the solid-liquid interface, with high density of cross junctions, which are interesting for molecular electronic circuit self-assembly.