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Aromaticpolycarboxylic acids can directly react with celluloseto form ester cross-linking structures and provide wrinkle resistancefunctions to cotton fabrics, different from aliphatic polycarboxylicacids, which will form anhydrides as intermediates. Sodium hypophosphiteis a catalyst proven effective in the reactions of both acids. Inorder to find alternative catalysts, the mechanism of the direct esterificationand the role of the catalyst in the reaction were investigated inthis study. Several sodium salts of phosphorous acid and dichloroaceticacid with varied pKavalues were employedin the treatment of cotton fabric with 3,3′,4,4′-benzophenonetetracarboxylic acid (BPTCA). The results confirmed that the overallreaction follows the Fischer esterification mechanism, an acid catalyzedreaction. The acid anions also play an important role in the reaction.Results of wrinkle recovery angles, FTIR band ratios of ester bonds,and thermogravimetric analyses of the treated fabrics consistentlysupported the mechanism. [ABSTRACT FROM AUTHOR]

Enzyme-linked immunosorbent assays (ELISA), as one of the most used immunoassays, have been conducted ubiquitously in hospitals, research laboratories, etc. However, the conventional ELISA procedure is usually laborious, occupies bulky instruments, consumes lengthy operation time, and relies considerably on the skills of technicians, and such limitations call for innovations to develop a fully automated ELISA platform. In this paper, we have presented a system incorporating a robotic-microfluidic interface (RoMI) and a modular hybrid microfluidic chip that embeds a highly sensitive nanofibrous membrane, referred to as the Robotic ELISA, to achieve human-free sample-to-answer ELISA tests in a fully programmable and automated manner. It carries out multiple bioanalytical procedures to replace the manual steps involved in classic ELISA operations, including the pneumatically driven high-precision pipetting, efficient mixing and enrichment enabled by back-and-forth flows, washing, and integrated machine vision for colorimetric readout. The Robotic ELISA platform has achieved a low limit of detection of 0.1 ng/mL in the detection of a low sample volume (15 μL) of chloramphenicol within 20 min without human intervention, which is significantly faster than that of the conventional ELISA procedure. Benefiting from its modular design and automated operations, the Robotic ELISA platform has great potential to be deployed for a broad range of detections in various resource-limited settings or high-risk environments, where human involvement needs to be minimized while the testing timeliness, consistency, and sensitivity are all desired.

In recent years, fluorescent carbon dots have attracted great attention due to their good luminescence and low toxicity. Here, blue fluorescent core-shell structured carbon polymer dots (CPDs) with high stability under a wide range of pH values, long storage time and excellent fluorescence in various solvents and even in solid state were prepared by hydrothermal synthesis of dendritic tris(2-aminoethyl)amine (TAEA) and citric acid. The CPDs core structure provides strong fluorescent luminescence, a shell structure of the core possesses high amount of dendritic primary amino groups connected by ethylene groups to the core. This unique structure prevents aggregation of the cores and self-quenching effect of CPDs. As a result, the CPDs have high fluorescence in both aqueous and hydrophobic solutions and even as pure solid-state powder. In addition, the CPDs are also insensitive to pH of solutions, and the fluorescence intensity of the solution was stable in the pH range of 4-14. The CPDs embedded polymer films and fibers revealed excellent fluorescent properties., Competing Interests: The authors declare no competing financial interest.

There is a critical need for new efficient solutions to purify and disinfect water from source to point-of-use, especially for the water contaminated by pathogenic microbes. Traditional disinfection technologies are chemically intensive and limited, either by biofouling or by the irreversible consumption of disinfectants. Herein, we present a scalable methodology to create biocidal and rechargeable nanofibrous membranes (BNF membranes) by combining N -halamine antimicrobial agent with electrospun nanofibers. Our method allows intrinsically rechargeable N -halamine moieties to covalently incorporate into nanofibers with high biocidal activity and durability. The resulting BNF membranes exhibit integrated properties of high porosity, large surface area, robust mechanical strength, super hydrophilicity, rechargeable chlorination capability (>3000 ppm), and high bactericidal efficacy (99.9999% contact-killing), which enabled the BNF membranes effectively disinfect bacteria-contained water by direct filtration, with promising high durability and fluxes (10000 L m -2 h -1 ). The successful synthesis of BNF membranes also provides a versatile platform for exploring the antimicrobial N -halamine materials in a self-supporting, structurally adaptive, and nanofibrous form.