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The passivation of nonspecific protein adsorption to paper is a major barrier to the use of paper as a platform for microfluidic bioassays. Herein we describe a simple, scalable protocol based on adsorption and cross-linking of poly(oligoethylene glycol methacrylate) (POEGMA) derivatives that reduces nonspecific adsorption of a range of proteins to filter paper by at least 1 order of magnitude without significantly changing the fiber morphology or paper macroporosity. A lateral-flow test strip coated with POEGMA facilitates effective protein transport while also confining the colorimetric reporting signal for easier detection, giving improved performance relative to bovine serum albumin (BSA)-blocked paper. Enzyme-linked immunosorbent assays based on POEGMA-coated paper also achieve lower blank values, higher sensitivities, and lower detection limits relative to ones based on paper blocked with BSA or skim milk. We anticipate that POEGMA-coated paper can function as a platform for the design of portable, disposable, and low-cost paper-based biosensors.

There is current interest in replacing petroleum-based additives in consumer paper products with abundantly available, renewable and sustainable biopolymers such as lignin-containing cellulose nanofibers (LCNFs) and cottonseed protein. This research characterized the performance of cottonseed protein isolate with/without LCNFs to increase the dry strength of filter paper. The application of 10% protein solution with 2% LCNFs as an additive improved the elongation at break, tensile strength and modulus of treated paper products compared to the improved performance of cottonseed protein alone. Improvements in tensile modulus and tensile strength were greatest for samples containing larger amounts of lignin and a greater degree of polymerization than for those with less lignin from the same biomass sources. [ABSTRACT FROM AUTHOR]

Active cellulose-based packaging materials were prepared by binding lactoferrin to paper modified with anionic polyelectrolytes. About 63% of the protein added in the slurry was present in the finished paper, corresponding to about 0.28 mg protein per cm2 of the glassine paper produced. The efficacy of the activated materials was assessed by microbiological trials, employing targets bacteria considered as spoilage and/or pathogens in food products. Lactoferrin-activated paper evidenced its efficacy against growing cells of E. coli and L. innocua, with a maximum of 0.3 and 1.3 log cycles reduction of the final population, respectively. These results can be considered a promising starting point and will be the focus of further research, aimed at developing innovative cellulose-based active food packaging. [ABSTRACT FROM AUTHOR]

Abstract: Conducting polymer–fibre composites with polypyrrole cellulose (paper) and protein (wool) fibres have been produced by polymerizing pyrrole with ferric chloride as the oxidant around separated individual cellulose (wood) fibres from bleached Pinus radiata Kraft pulp, and merino wool fibres respectively to generate new composite materials that retain the inherent properties of the polymer and individual fibres. For the polypyrrole–cellulose composite, the polypyrrole consisted of spheres of about 100nm in size fused together to form a continuous coating that fully encapsulates the cellulose fibre and associated finer fibrils. For the polypyrrole–wool composite the polypyrrole formed a similar coating of about 200nm spheres. Electrical conductivities of the composites were substantially increased over those of the precursor fibres. [Copyright &y& Elsevier]