Nanoengineering and green chemistry-oriented strategies toward nanocelluloses for protein sensing.

As one of the most important functional organic macromolecules of life, proteins not only participate in the cell metabolism and gene regulation, they also earnestly protect the body's immunity system, leading to a powerful biological shield and homeostasis. Advances in nanomaterials are boosting the significant progress in various applications, including the sensing and examination of proteins in trace amount. Nanocellulose-oriented protein sensing is at the forefront of this revolution. The inherent feature of high biocompatibility, low cytotoxicity, high specific area, good durability and marketability endow nanocellulose with great superiority in protein sensing. Here, we highlight the recent progress of protein sensing using nanocellulose as the biosensor in trace amount. Besides, various kinds of construction strategies for nanocelluloses-based biosensors are discussed in detail, to enhance the agility and accuracy of clinical/medical diagnostics. Finally, several challenges in the approbatory identification of new approaches for the marketization of biomedical sensing that need further expedition in the future are highlighted.

Two-dimensional defective black phosphorus/BiVO4 nanoheterojunctions for molecular nitrogen activation.

Solar-driven transfer of nitrogen into ammonia is still challenging as a result of the strong dipole moment of the NN triple bond. Molecular nitrogen activation to construct the reactive active nitrogen species (RNS) is the key aspect for the highly efficient solar N2 conversion. Herein, we selected black phosphorus-BiVO4 (BP-BiVO4) as a model system to clarify the significance of the inherent defective state to the molecular nitrogen activation over the formed heterojunctions. Oxygen vacancies (OVs) induced BP-BiVO4 heterojunctions (OV-BP-BiVO4) were controllably fabricated through quasi-reverse-emulsion approach. OVs in the lattice of the heterojunctions were introduced by the pulsed laser irradiation, which to a great extent determined the kinetics, energetics, and mechanism of the photocatalytic N2 reduction. Systematic experiments revealed that the optimized heterojunction interfaces and rich OVs states led to superior ability in the activation of active molecular nitrogen (N2 â†’ RNS â†’ NH3). This work brightens defective and interfacial perspectives for the construction of efficient heterojunctions to produce reactive nitrogen species with high photocatalytic activity, and extend their potentials to a wide variety of other inorganic/organic transformations.

Li-N2 Batteries: A Reversible Energy Storage System?

Tremendous energy consumption is required for traditional artificial N2 fixation, leading to additional environmental pollution. Recently, new Li-N2 batteries have inextricably integrated energy storage with N2 fixation. In this work, graphene is introduced into Li-N2 batteries and enhances the cycling stability. However, the instability and hygroscopicity of the discharge product Li3 N lead to a rechargeable but irreversible system. Moreover, strong nonpolar N≡N covalent triple bonds with high ionization energies also cause low efficiency and irreversibility of Li-N2 batteries. In contrast, the modification with in situ generated Li3 N and LiOH restrained the loss and volume change of Li metal anodes during stripping and plating, thereby promoting the rechargeability of the Li-N2 batteries. The mechanistic study here will assist in the design of more stable Li-N2 batteries and create more versatile methods for N2 fixation.

Nitrogen self-doped carbon aerogels derived from trifunctional benzoxazine monomers as ultralight supercapacitor electrodes.

Ultralight benzoxazine-derived porous nitrogen self-doped carbon aerogels with good yield can be prepared by direct polymerization of trifunctional benzoxazine monomers under acid catalysis using concentrated hydrochloric acid. This allows for a significantly widened density range (0.8-4.5 mg cm-3) and avoids any sacrificial etching. When serving as electrode materials for supercapacitors, the resulting hierarchical porous carbon aerogels show ultrahigh specific capacitance, excellent rate performance and good cycling stability (retention of 97.3% even after 10 000 continuous charge-discharge cycles). Besides energy storage devices, the interconnected nanoporous carbon aerogels can also find applications in oil/water separation, heavy metal removal, catalyst supports, and so forth.

Bis{2-[3-(dimethyl-amino)propyl-imino-meth-yl]-4,6-dihydro-seleno-phenolato}zinc(II).

In the title complex, [Zn(C(12)H(17)N(2)OSe(2))(2)], the Zn(II) ion is six-coordinated by two N,N',O-tridentate Schiff base ligands, resulting in a slightly distorted trans-ZnO(2)N(4) octa-hedral coordination for the metal ion.

4,4',6,6'-Tetra-hydro-seleno-2,2'-[(E,E)-cyclo-hexane-1,2-diylbis(nitrilo-methyl-idyne)]diphenol.

In the title mol-ecule, C(20)H(22)N(2)O(2)Se(4), the dihedral angle between the pendant aromatic rings is 67.1 (2)°. The conformation is stabilized by two intra-molecular O-H⋯N hydrogen bonds.

Diaqua-bis[2-(4-bromo-phen-yl)acetato]bis-(N,N-dimethyl-pyridin-4-amine)copper(II).

In the title compound, [Cu(C(8)H(6)BrO(2))(2)(C(7)H(10)N(2))(2)(H(2)O)(2)], the Cu(II) atom (site symmetry ) adopts a Jahn-Teller-distorted trans-CuN(2)O(4) octa-hedral coordination, with the aqua O atoms in axially extended sites. An intra-molecular O-H⋯O hydrogen bond helps to establish the conformation and an inter-molecular O-H⋯O hydrogen bond is seen in the crystal packing.