Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to covalently immobilize small molecules, proteins and DNA onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane’s bioactivity was specific, dose-dependent, and stable over a long period of time. Use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices.

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SynopsisPolyamides were prepared from C6 to C 1 2 diamines with brassylic acid, a linear C,:, dicarboxylic acid, derived from Crambe seed oil. One distinct characteristic of these polymers is their low moisture adsorption as compared to nylon 66 and nylon 6. To modify the properties of these nylons, multicomponent copolyamides were prepared from hexamethylene diamine and mixtures of brassylic acid with adipic, terephthalic, or isophthalic acids. It was found that the melting points of the copolyamides were changed by the choice and the levels of the diacids used. The melting pointcomposition curves all show a eutectic minimum. The glass transition temperature of nylon 6,13 is also changed by the incorporation of other diacids. Water adsorption of nylon 6,13 increases with increased substitution of brassylic acid by other diacids in the order ofadipic > isophthalic 2 terephthalic. Mechanical properties of some copolyamides are in the same range as the commercial nylon 11 and nylon 12. The low moisture absorption, reduced fabrication temperature, and the wide range of properties obtainable through copolymerization make copolyamides derived from brassylic acid potentially suitable as specialty tubing, powder coatings, and molded machine parts. They will be commercially viable when brassylic acid becomes available on a large scale and is competitively priced.

Copolyamides with mixtures of adipic and terephthalic acids in various mole rations and three types of diamine were prepared, and a melting point vs. composition curve for each system was constructed. The three types of diamine were: (1) straight‐chain aliphatic diamines with six to twelve carbon atoms, (2) m‐xylylenediamine, and (3) 4,4‐dimethyl‐1,7‐heptanediamine. These curves for copolyamides containing straight chain aliphatic diamines had no minimum at the intermediate ranges of composition. The curve for m‐xylylene diamine had a minimum at a point corresponding to 77 mole‐% of adipic acid. The copolyamide containing 4,4‐dimethyl‐1,7‐heptanediamine was not crystalline. Evidence suggested that isomorphous replacement of adipic and terephthalic acids in copolyamide systems was greatly influenced by the structure of the diamine, possibly through the bulk effect of its substituents on chain‐packing.