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Antibacterial wound dressings can effectively avoid the residual of antibacterial nanomaterials for injection in vivo, reduce their biological toxicity to normal cells and tissues, making them be widely applied in biomedical field. Herein, an approach of combining ion-crosslinking, in-situ reduction and microwave-assisted methods was employed to prepare chitosan-copper-gallic acid nanocomposites (CS-Cu-GA NCs) with dual-functional nano-enzyme characteristics (oxidase- and peroxidase-like functions). The oxidase-like activity of CS-Cu-GA NCs can facilitate the production of hydrogen peroxide (H 2 O 2 ) when it contacted with physiologically relevant antioxidants (AH 2 ) in bacteria. Subsequently, H 2 O 2 was catalyzed to generate hydroxyl radicals (OH) under the peroxidase-like activity of CS-Cu-GA NCs. Furthermore, CS-Cu-GA NCs integrate the inherent antibacterial properties of chitosan, Cu NPs and Cu 2+ . Animal experiments revealed that the antibacterial dressing incorporating CS-Cu-GA NCs exhibited its effective promotion of S. aureus-infected wounds healing, as well as no damage to normal tissues. Besides, the antibacterial dressing was prepared to a band aid with excellent water swelling and antibacterial properties, which was further fixed in a medical tape to construct a portable antibacterial product that can be applied to the surface of human skin and showed excellent waterproof performance, providing a new insight for the construction of clinical antibacterial wound healing products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Herein, a label-free and dual-readout immunochromatographic test strip (ITS) for the sensitive detection of Escherichia coli (E. coli) O157:H7 by taking advantages of the strong capture ability of Fe 3 O 4 @CuS nanostructures (NSs) towards bacteria and their ultrahigh photothermal effects (PTEs) was reported. Especially, without the customarily antibody (Ab)-labeled probe, Fe 3 O 4 @CuS NSs could be adsorbed onto the surfaces of bacteria to form Fe 3 O 4 @CuS-bacteria conjugates and then trapped by immobilized Abs on the test line (T-line), forming a characteristic yellow band. After direct immunoreactions, the PTEs of Fe 3 O 4 @CuS NSs endowed T-line to be irradiated by an 808 nm infrared light, obtaining satisfactory sensitivity and accuracy. Under optimal conditions, E. coli O157:H7, as low as 10 3 and 10 2 CFU/mL, could be monitored in colorimetric and photothermal modes. Additionally, E. coli O157:H7 was successfully detected in beef, chicken, milk and honey samples by this proposed platform with a recovery of 80-120%., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Due to the strong electron‐withdrawing nature and high lipophilicity of trifluoromethoxy group (OCF3), methods for introducing OCF3 into organic molecules are in high demand. However, the research area of direct enantioselective trifluoromethoxylation is still in the embryonic stage, with limited enantioselectivity and/or reaction types. Here, we describe the first copper‐catalyzed enantioselective trifluoromethoxylation of propargyl sulfonates using trifluoromethyl arylsulfonate (TFMS) as the trifluoromethoxy source in up to 96 % ee. [ABSTRACT FROM AUTHOR]

In water treatment, it is a valid way to remove Cu(II) efficiently via layered double hydroxides (LDHs) intercalated with chelate, but the desorption and its mechanism remain an unsolved difficult problem. To solve this problem, MgAl LDHs intercalated with EDTA (MgAl‐EDTA‐LDHs) was synthesized by one‐step co‐precipitation method, and applied to recover Cu2+. The characterizations of SEM, XRD, XPS, EA and AAS were employed, and the results showed that MgAl‐EDTA‐LDHs exhibited a typical lamellar structure, the adsorption capacity of MgAl‐EDTA‐LDHs on Cu2+ could reach 79.69 mg/g, which was attributed to the chelation of EDTA and chemical bonding of hydroxyl (−OH) on the surface of LDHs layers. In addition, the adsorption capacity could achieve 45.75 mg/g after eluting by Na2CO3 solution, which was relevant to the ion exchange by CO32−. Herein, the adsorption and desorption mechanism of MgAl‐EDTA‐LDHs on Cu2+ was expounded, which may pave a new way to recover the heavy metal and provide a theoretical guidance for future research. [ABSTRACT FROM AUTHOR]