Bacteria responsive color-changing wound dressings offer a valuable platform for continuous monitoring of the wound bed facilitating early detection of bacterial infections. In this study, we present a highly sensitive electrospun nanofibrous polyurethane wound dressing incorporating a hemicyanine-based chromogenic probe with a labile ester linkage that can be enzymatically cleaved by bacterial lipase released from clinically relevant strains, such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA). A rapid chromogenic response was achieved by localizing the dye at the surface of core−shell fibers, resulting in a 5x faster response relative to conventional nanofibers. By incorporating polyvinylpyrrolidone (PVP) dopant in the shell, the sensitivity was boosted to enable detection of bacteria at clinically relevant concentrations after 2 h exposure: 2.5 × 10 5 CFU/ cm 2 P. aeruginosa and 1.0 × 10 6 CFU/cm 2 MRSA. Introduction of PVP in the shell also boosted the degree of hydrolysis of the chromogenic probe by a factor of 1.2× after a 3 h exposure to a low concentration of P. aeruginosa (10 5 CFU/cm 2 ). PVP was also found to improve the discernibility of the color change at high bacterial concentrations. The cooperativity between the chromogenic probe, fiber structure, and polymer composition is well-suited for timely in situ detection of wound infection.

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have been employed to endow surfaces with antimicrobial properties. Common strategies for developing antimicrobial textiles involve impregnating or coating the textiles with an active agent such as copper nanoparticles, copper oxide particles, copper sulfide, benzalkonium chloride, polybiguanide, iodine complexed with N-vinylpyrrolidone, salt coating, licorice root extract, silver nanoparticles, titanium dioxide, aluminum and aluminum oxide, anionic photosensitizers (rose Bengal and sodium 2-anthraquinone sulfate), zinc oxide, or graphene-based nanomaterials such as graphene oxides, nanofibers, nanosheets, and nanoparticles. [1,2,[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] However, such strategies that rely on impregnating surfaces with antimicrobial agents are subject to leaching of the active compound, posing health risks to the wearer as well as causing environmental contamination through laundering and textile end-of-life disposal. [18] Covalent surface modification of textiles with antimicrobial agents can mitigate these risks.Covalent modification of antimicrobial polymers onto textile surfaces can be achieved by a variety of methods, such as graft polymerization via chemical free radical initiators, click chemistry, or radiation-induced graft polymerization. Radiation-induced graft polymerization can be accomplished by UV, plasma, electron beam or gamma radiation for surface modification with polar monomers, and offers several inherent advantages such

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Whether stored-grain insects can communicate with each other inside stored-grain bulks is an important question for the development of pest management programs. Movements of the individual adults of Cryptolestes ferrugineus towards caged adult(s), in the presence or absence of wheat, were studied inside an apparatus (10 cm length), using an infrared camera. The numbers of the caged adults were 1, 20, or 50 of females or males, and 100 or 200 mixed-sex adults. Without grain, both males and females moved towards the caged single male, but not the caged single female. With grain, neither males nor females moved towards the caged single male or female. When 50 males were added to the cage, females did move significantly towards the caged males. There were trends for introduced males and females to move towards caged males at higher densities.