A composite membrane based on polycaprolactone (PCL) and cellulose nanofibers (CNF) with different compositions was prepared using the electro-spinning method, with the objective of developing organic membranes with good mechanical properties to remove contaminants from water. Water is a resource of primary importance for life and human activities. In this sense, cellulose obtained from agave bagasse and polycaprolactone nanofibers was used to prepare membranes that were tested by filtering tap water. The membranes obtained presented a porosity and structure on a nanometric scale. The water quality variables evaluated after filtration with the PCL/CNF membranes showed 100% turbidity removal, 100% conductivity, and heavy metal removal of the order of 75% to 99% for iron and chromium. CNF comprises biowaste derived from tequila production, and it has added value. Electro-spun CNF and PCL membranes can be applied as a "green" and eco-friendly filtration system for water purification.Molecules 2020, 25, 683 2 of 13 about 40% (wet basis) of over 1000 tons of agave grown in Mexico [11]. The availability of such large quantities of agave bagasse [9] poses serious disposal problems, since most of the biomass ends up in clandestine dumps (due to little environmental regulation), causing adverse effects on the fertility of farmland [12], contamination by leachates, and phytosanitary risks due to the inadequate incorporation of this material into the soil [13]. Chemically, agave bagasse is 44.5% cellulose, 25.3% hemicellulose, and 20.1% lignin [7]. Taking advantage of these constituents, there have been many efforts to use agave bagasse for various applications, e.g., the production of biopolymers [14,15], composting [16], animal nutrition [17], generation of biofuels [10,18], reinforcement materials [19], etc. More recently, agave bagasse is being explored for the production of cellulose nanofibers and nanocrystals [7,8,20,21] to further diversify the utilization of this biowaste. On the other hand, electro-spinning of biopolymers has become popular in the manufacture of nanofibers for a variety of added value applications, such as tissue engineering, drug release, sensors, and air and liquid filtration systems [22][23][24][25][26].Our main interest in electro-spinning agave cellulose nanofibers was to produce membranes that can retain suspended particles in water (due to the diameter of the fibers), a membrane with high porosity and good surface area properties. However, the main challenge with the preparation of electro-spun agave cellulose was the poor solubility of cellulose that was to be dispersed into an electro-spinnable liquid [24]. We overcame the poor solubility challenge by dissolving agave cellulose in dimethylformamide (DMF) and blending with polycaprolactone to prepare a composite electro-spun blend, subsequently producing electro-spun nanocellulose and polycaprolactone membranes. The main objective of using a copolymer blend was to improve technical properties, such as contaminant retention capacity, therma...

No abstract

No abstract

Consumption of cranberries is associated with the putative effects of preventing urinary tract infections (UTIs). Cranberry proanthocyanidins (PAC) contain unusual double A-type linkages, which are associated with strong interactions with surface virulence factors found on UTI-causing bacteria such as extra-intestinal pathogenic Escherichia coli (ExPEC), depicting in bacterial agglutination processes. In this work, we demonstrated the efficacy of cranberry PAC (200 μg/mL) to agglutinate ExPEC (5.0×108 CFU/mL) in vitro as a selective interaction for the design of functionalized biosensors for potential detection of UTIs. We fabricated functionalized screen-printed electrodes (SPEs) by modifying with PAC-polyaniline (PANI) nanocomposites and tested the effectiveness of the PAC-PANI/SPE biosensor for detecting the presence of ExPEC in aqueous suspensions. Results indicated that the PAC-PANI/SPE was highly sensitive (limit of quantification of 1 CFU/mL of ExPEC), and its response was linear over the concentration range of 1–70,000CFU/mL, suggesting cranberry PAC-functionalized biosensors are an innovative alternative for the detection and diagnosis of ExPEC-associated UTIs. The biosensor was also highly selective, reproducible, and stable.

No abstract