Latest ArticlesThe preparation of silver nanoparticles (AgNPs) with microbe or plant tissues as bio-template offers green approach, while it suffers from low harvest and purification is needed. Herein, we propose a facile protocol for one-pot preparation of AgNPs using M13 phage as bio-template by simply mixing AgNO3 solution with alkali M13 phage. In the obtained AgNPs-M13 phage composite, Cr(Ⅲ) selectively coordinates with the amino residues on phage surface and leads to the aggregation of AgNPs through the bridging of M13 phages. This makes it feasible for colorimetric sensing of Cr(Ⅲ) by measuring the absorbance ratio of AgNPs at 600 and 405 nm, which provides a LOD of 14 nmol/L. The composite also showed favorable bactericidal activity for both Gram-positive and Gram-negative bacteria, making it a promising candidate as antibacterial film in chromium-containing dental alloys and meanwhile serve as a sensing probe for monitoring the corrosion of the dental alloys.
Graphene oxide (GO) is widely used in the construction and application of various 2D membrane-based materials due to its unique colloidal structure. Herein, we demonstrate that micrometer-sized particles can make up freestanding membranes enabled by the extraordinary amphiphilic and polymer-like properties of graphene oxide through freeze casting. The 2D macromolecule, GO could well wrap the particles for better uniformity and stability in either dispersion or membrane. Importantly, freeze casting plays an important role in avoiding the severe aggregation of micrometer-sized particles in the solventremoving process. After reduction, the membrane exhibits good electrical conductivity while maintaining its integral structure, which can be directly used as a freestanding binder-free electrode. This work provides a universal approach to fabricate freestanding membranes with various micrometersized materials for energy storage.
Hard carbon is regarded as promising anode materials for potassium-ion batteries (KIBs) owing to their low price and easy availability. However, the limited rate capability still needs to be improved. Herein, we demonstrate the fabrication of oxygen/sulfur co-doped hard carbon through a facile hydrolyzationsulfuration process of skimmed cotton. The simultaneous dopants significantly improve potassium ion diffusion rate. When served as the anode for KIBs, this hydrolyzed hard carbon delivered a high reversible capacity (409 mAh/g at 0.1 A/g), superior rate capability (135 mAh/g at 2 A/g) and excellent cyclability (about 120 mAh/g overt 500 cycles at 2 A/g). This work provides a facile strategy to prepare low-cost doped-hard carbon with superior potassium storage property.
Alkaline phosphatase (ALP) is one of essential biomarkers in mammalian tissue. Here we report a ratiometric probe for ALP, which is rationally designed and synthesized by employing ESIPT fluorophore N-(3-(benzo[d]thiazol-2-yl)-4-hydroxyphenyl)benzamide (BTHPB). The enzymatic dephosphorylation converts the probe to BTHPB, which exhibits a large spectral red-shift (120 nm), allowing extremely high sensitivity of ALP sensing at 0.004 mU/mL. The probe also shows excellent biocompatibility and has been applied for monitoring the endogenic ALP in living cells.
TNFR1-associated death domain protein (TRADD) with arginine N-GlcNAcylation is a novel and structurally unique posttranslational modification (PTM) glycoprotein that blocks the formation of death-inducing signaling complex (DISC), orchestrating host nuclear factor kB (NF-kB) signaling in entero-pathogenic Escherichia coli (EPEC)-infected cells. This particular glycosylated modification plays an extremely vital role for the effective colonization and pathogenesis of pathogens in the gut. Herein we describe the total synthesis of TRADD death domain (residues 195-312) with arginine235 N-GlcNAcylation (Arg-GlcNAc TRADD (195-312)). Two longish peptidyl fragments of the wild-type primary sequence were obtained by robust, microwave-assisted, highly efficient, solid-phase peptide synthesis (SPPS), the N-GlcNAcylated sector was built by total synthesis and attached specifically to resinbound peptide with an unprotected ornithine residue via silver-promoted on-resin guanidinylation, Arg-GlcNAc TRADD (195-312) was constructed by hydrazide-based native chemical ligation (NCL). The facile synthetic strategy is expected to be generally applicable for the rapid synthesis of other proteins with Arg-GlcNAc modification and to pave the way for the related chemically biological study.
Highly luminescent colloidal nanocrystals have wide applications in bioimaging and various optoelectronic devices. Herein we report a facile and mild procedure by combining S2- treatment and binary ligand passivation, which can efficiently enhance the luminescent property of CdSe nanocrystals at room temperature. The photoluminescence quantum yield of as-treated CdSe nanocrystals exhibits drastic enhancement (e.g., 188 times for CdSe nanorods) after this dual-passivation treatment. The methodology proposed here can be applied to various CdSe nanocrystals, regardless of their sizes, shapes, and crystal structures.
Recently, the development of new electrode materials for lithium-ion batteries (LIBs) has received intensive attention. As an important family of inorganic materials, mixed Mo-based transition metal oxides system is focused as anode materials. In the present work, a simple route has been adopted for the synthesis of layered-flake-like β-SnMoO4 Nano-assemblies, which have been explored as potential anode materials for the first time in lithium-ion battery (LIB). Overall, the current reports on metal molybdate as anode materials are still rarely. As the anode material for LIBs, it was observed that the fabricated anode is capable of delivering a steady state capacity of almost 400 mAh/g up to 300 cycles under the influence of 200 mA/g current density. Further, the anode material is suitable for use as a rated capacity anode because of its high current density tolerance. The present study can be further extended for the generation of a wide variety of other novel materials for multidisciplinary energy related applications.
Gold nanoparticles functionalized hollow mesoporous Prussian blue nanoparticles (Au@HMPB NPs) were synthesized and its peroxidase-like activity was explored for electrochemical probe. The Au@HMPB NPs can reduce H2O2 at low detection potential of -0.1 V with high sensitivity. After physically adsorption of antibodies onto the gold nanoparticle surface, the functionalized nanoparticles were turned into immuno-probe. The soluble α-chain of interleukin-2 (IL-2) receptor (sCD25) was chosen as a model protein biomarker to test the performance of the probe. sCD25 in the samples were captured and enriched by capture anti-CD25 antibody functionalized magnetic nanospheres. Detection antibody functionalized Au@HMPB can then be linked onto the nanospheres and generate electrochemical current towards H2O2 reduction. The electrochemical responses to 1 mmol/L H2O2 was increased with the increasing concentration of CD25.
The development of polymeric optical materials with a higher refractive index, transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as microlenses, image sensors, and organic light-emitting diodes. Most acrylates have a low refractive index (around 1.50) which does not meet the high performance requirements of advanced optical materials. In this research, three novel acrylates were synthesized via a facile one-step approach and used to fabricate optical transparent polymers. All of the polymers reveal good optical properties including high transparency (≥90%) in the visible spectrum region and high refractive index values (1.6363) at 550 nm. Moreover, nanostructures of these acrylate polymers with various feature sizes including nanogratings and photonic crystals were successfully fabricated using nanoimprint lithography. These results indicate that these acrylates can be used in a wide range of optical and optoelectronic devices where nanopatterned films with high refractive index and transparency are required.
The core-shell structured Au@Bi2S3 nanorods have been prepared through direct in-situ growth of Bi2S3 at the surface of pre-synthesized gold nanorods. The product was characterized by X-ray diffraction, transmission electron microscopy and energy-dispersive X-ray spectroscopy. Then the obtained Au@Bi2S3 nanorods were coated onto glassy carbon electrode to act as a scaffold for fabrication of electrochemical DNA biosensor on the basis of the coordination of -NH2 modified on 5'-end of probe DNA and Au@Bi2S3. Electrochemical characterization assays demonstrate that the Au@Bi2S3 nanorods behave as an excellent electronic transport channel to promote the electron transfer kinetics and increase the effective surface area by their nanosize effect. The hybridization experiments reveal that the Au@Bi2S3 matrix-based DNA biosensor is capable of recognizing complementary DNA over a wide concentration ranging from 10 fmol/L to 1 nmol/L. The limit of detection was estimated to be 2 fmol/L (S/N=3). The biosensor also presents remarkable selectivity to distinguish fully complementary sequences from basemismatched and non-complementary ones, showing great promising in practical application.