Publications by authors named "M D Cerqueira"

This study investigates the effect of different linkers and solvents on the immobilization of DNA probes on graphene surfaces, which are crucial for developing high-performance biosensors. Quartz crystal microbalance with dissipation (QCM-D) measurements were used to characterize in situ and real-time the immobilization of ssDNA and hybridization efficiency on model graphene surfaces. The DNA probes immobilization kinetics and thermodynamics were systematically investigated for all the pairings between three bifunctional linkers─1-pyrenebutyric acid succinimidyl ester (PBSE), Fluorenylmethylsuccinimidyl carbonate (FSC), and Acridine Orange (AO) succinimidyl ester─and three organic solvents (DMF, DMSO, and 10% DMF/ethanol).

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Nanoparticles based on food-grade materials are promising materials to develop Pickering emulsions for food applications. Initially, this study focuses on the development of nanoparticles through the utilization of a soluble complex of whey protein concentrate (WPC) and cress seed gum (CSG), which were modified by calcium chloride (CaCl) as a cross-linker. The response surface methodology was used to investigate the impact of different concentrations of WPC (1-4% /), CSG (0-1% /), and CaCl (1-3 mM) on particle size, polydispersity index (PDI), and Zeta potential.

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Oleogels are semi-solid systems that can function both as replacers of trans and saturated fats and/or as carriers of lipophilic bioactive compounds. However, bioactive compounds can affect the structure of the oleogel matrix and this effect depends on the properties of such compounds. Therefore, the aim of this study was to develop oleogels loaded with β-carotene (BC) or resveratrol (R), with low concentrations of glycerol monostearate (GMS, 2-5 wt%) and sunflower oil as organic solvent.

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Composition and structure of oleogels significantly influence their digestive behaviour, impacting triacylglycerol breakdown and the bioavailability of incorporated compounds. Texture profile analysis showed that sterol-based oleogels (STOs) exhibited 20 times higher hardness than beeswax-based oleogels (BWOs), which showed stronger cohesion due to elasticity sustained by adhesive forces. Tribological assessments revealed similar initial coefficients of friction (COF) for both oleogels.

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This work aims to develop a bio-based fibrous material that is able to adsorb and degrade chemical and biological hazardous agents. Thus, cellulosic fabrics (flax) were functionalized with chitosan (CS) and poly(ethylene oxide) (PEO) electrospun nanofibers doped with titanium dioxide (TiO) and cerium dioxide (CeO) nanoparticles (NPs). The electrospray deposition of these NPs was also tested.

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