Early diagnosis of diseases is of great importance because it increases the chance of a cure and significantly reduces treatment costs Thus, development of rapid, sensitive, and reliable biosensing techniques is essential for the benefits of human life and health As such, various nanomaterials have been explored to improve performance of biosensors, among which, carbon dots (CDs) have received enormous attention due to their excellent performance In this Review, the recent advancements of CD-based biosensors have been carefully summarized First, biosensors are classified according to their sensing strategies, and the role of CDs in these sensors is elaborated in detail Next, several typical CD-based biosensors (including CD-only, enzymatic, antigen-antibody, and nucleic acid biosensors) and their applications are fully discussed Last, advantages, challenges, and perspectives on the future trends of CD-based biosensors are highlighted

Recent Developments of Carbon Dots in Biosensing: A Review.

One-dimensional wires are the most common building blocks in metamaterials. In this study, zero-dimensional nanoparticles connected by tunneling networks were used to construct metamaterials, thus providing a more flexible alternative for designing the geometrical configuration of metamaterials, particularly in nanodevices. The composites with nickel nanoparticles@MnO were prepared by a bio-gel derived strategy. Nickel nanoparticles were not connected geometrically, but the conductive network had been already formed, which was a tunneling-dominated percolative phenomenon demonstrated by the first-principles calculation. Negative permittivity was achieved in the composites, as the low-frequency plasmonic state could be generated in the tunneling nickel-networks. At the same time, negative susceptibility was observed due to the diamagnetism of the tunneling current loops. Electromagnetic simulations indicate that the composites have the potential for electromagnetic shielding (only 0.25 mm in thickness). It is believed that this study not only fills up the research gap in the influence of the tunneling effect on negative electromagnetic parameters but also opens up another way of preparing metamaterials by using zero-dimensional nanoparticles instead of one-dimensional wires.

/pdf/tunneling-induced-negative-permittivity-in-ni-mno-32ceshft9l.pdf

Tunneling-induced negative permittivity in Ni/MnO nanocomposites by a bio-gel derived strategy

Two-dimensional crystals have emerged as a class of materials that may impact future electronic technologies. Experimentally identifying and characterizing new functional two-dimensional materials is challenging, but also potentially rewarding. Here, we fabricate field-effect transistors based on few-layer black phosphorus crystals with thickness down to a few nanometres. Reliable transistor performance is achieved at room temperature in samples thinner than 7.5 nm, with drain current modulation on the order of 10(5) and well-developed current saturation in the I-V characteristics. The charge-carrier mobility is found to be thickness-dependent, with the highest values up to ∼ 1,000 cm(2) V(-1) s(-1) obtained for a thickness of ∼ 10 nm. Our results demonstrate the potential of black phosphorus thin crystals as a new two-dimensional material for applications in nanoelectronic devices.

http://absimage.aps.org/image/MAR14/MWS_MAR14-2013-005031.pdf

Black Phosphorus Field-effect Transistors

N self-doped ZnO derived from microwave hydrothermal synthesized zeolitic imidazolate framework-8 toward enhanced photocatalytic degradation of methylene blue.

Multifunctions of Polymer Nanocomposites: Environmental Remediation, Electromagnetic Interference Shielding, And Sensing Applications

High-absorption solar steam device comprising Au@Bi2MoO6-CDs: extraordinary desalination and electricity generation

Chemical vapor deposition (CVD)-grown 2D materials like MoS2 and WS2 have been widely used for research and application. Here, we study substrates’ effects on CVD-grown MoS2 and WS2. The morphology, crystalline quality and optical properties have been modified while changing substrates, which can be derived from lattice matching between 2D materials and substrate, defect/impurities on the interface and conductance/transparency of different substrates. The results provide suggestion for further study in CVD growth of 2D materials and device fabrications.

Substrate effects on the CVD growth of MoS2 and WS2

Visible light photo-treatment of simulated wastewater activated by high-efficient photocatalyst: A novel heterojunction of Bi2MoO6 balls and Pd nanoskeletons

Large-area uniform few-layer PtS2: Synthesis, structure and physical properties

To develop next-generation electronic devices, novel semiconductive materials are urgently required. The transition metal dichalcogenides (TMDs) hold the promise of next generation of semiconductor materials for emerging electronic applications. As a member of the group-10 TMDs, PdS2 has a notable layer-number-dependent band structure and tremendously high carrier mobility at room temperature. Here, we demonstrate the experimental realization of centimeter-scale synthesis of the few-layer PdS2 by the combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods. For the first time, the optical anisotropic properties of the few-layer PdS2 were investigated through angle-resolved polarized Raman spectroscopy. Also, the evolution of Raman spectra was studied depending on the temperature in the range of 12-300 K. To further understand the electronic properties of the few-layer PdS2, the field-effect transistor (FET) devices were fabricated and investigated. The electronic measurements of such FET devices reveal that the PdS2 materials exhibit a tunable ambipolar transport mechanism with field-effect mobility of up to ∼388 cm2 V-1 s-1 and the on/off ratio of ∼800, which were not reported before in the literature. To well understand the experimental results, the electronic structure of PdS2 was determined using density functional theory (DFT) calculations. These excellent physical properties are very helpful in developing high-performance opto-electronic applications.

Xudong Zhang

Papers

High-absorption solar steam device comprising Au@Bi2MoO6-CDs: extraordinary desalination and electricity generation

Substrate effects on the CVD growth of MoS2 and WS2

Visible light photo-treatment of simulated wastewater activated by high-efficient photocatalyst: A novel heterojunction of Bi2MoO6 balls and Pd nanoskeletons

Large-area uniform few-layer PtS2: Synthesis, structure and physical properties

Centimeter-Scale Few-Layer PdS2: Fabrication and Physical Properties.