Chitosan/bacterial cellulose composite films containing diamond nanoparticles (NDs) with potential application as wound dressing are introduced. Microstructural studies show that NDs are uniformly dispersed in the matrix, although slight agglomeration at concentrations above 2 wt % is seen. Fourier transform infrared spectroscopy reveals formation of hydrogen bonds between NDs and the polymer matrix. X-ray diffraction analysis indicates reduced crystallinity of the polymer matrix in the presence of NDs. Approximately 3.5-fold increase in the elastic modulus of the composite film is obtained by the addition of 2 wt % NDs. The results of colorimetric analysis show that the composite films are transparent but turn to gray-like and semitransparent at high ND concentrations. Additionally, a decrease in highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) gap is also seen, which results in a red shift and higher absorption intensity towards the visible region. Mitochondrial activity assay using L929 fibroblast cells shows that the nanocomposite films are biocompatible (>90%) after 24 h incubation. Multiple lamellapodia and cell-cell interaction are shown. The results suggest that the developed films can potentially be used as a flexible platform for wound dressing.

Magnetic nanoparticles (MNPs) were deposited onto multiwalled carbon nanotubes (MWCNTs) by in situ high-temperature decomposition of the magnetic precursor [iron(III)] and MWCNTs, in ethylene glycol. This one-step synthetic method was applied to commercially available carbon nanotubes (CNTs). Scanning electron micrographs of the resulting products revealed that MNPs decorated the surface of the MWCNTs. The hybrid nanoparticles thus obtained were used for sampling and cleanup in the determination of eight fluoroquinolones (FQs) and two quinolones (Qs) at trace levels by ultra performance liquid chromatography (UPLC). A systematic study of analyte adsorption and desorption was conducted with MNPs and MWCNTs separately. Although both solid phases adsorbed the analytes to some extent, the much higher recoveries were obtained by using the MNP-MWCNT composite which was thus selected to treat plasma samples containing FQs and Qs. Lower accuracies were determined at spiked plasma compared to the standard solution caused by the complexation affinity of the analytes with proteins because high recoveries were observed when deproteinization was performed before treating the sample with the magnetic MWCNTs. The performance characteristics of the optimized method were determined, and the method was applied to the analysis of plasma samples from antibiotic-treated patients. On the basis of the results, the use of an in situ synthesized MWCNT-MNP composite allows the simple, expeditious sampling and treatment of such complex biological samples for the subsequent determination of FQs and Qs present at free form.

21To attend the growing consumer demand for novel ready-to-eat fresh cut fruits packaging polylactic acid 22 (PLA)-based active packaging was realized. The aim of these packaging is to provide an improved 23 protection and even to extend their shelf-life. PLA-based active packaging was prepared by adding 24 nanoclays and surfactants in its formulation. The evaluation of PLA-nanocomposite packaging was done 25 in comparison to pristine PLA and conventional plastic (polyethylene terephthalate, PET) using fresh-26 cut melons. Physicochemical properties were investigated by the means of weight loss, visual 27 appearance, pH, colour, and firmness. In addition, microbial profile was tested via microbiological 28 assays. In order to evaluate the environmental impact of PLA-based active packaging compared to 29 commonly used PET, life cycle assessment (LCA) was conducted. In terms of physicochemical and 30 antimicrobial properties, the results clearly showed that the presence of nanoclays and surfactants in the 31 PLA formulations improved their performance, thus contributing to bring the characteristic and 32 behaviour of PLA packages close to those of PET. Furthermore, assessment of life cycle environmental 33 impacts indicated that PLA packaging with nanoclays had the highest environmental performance. 34 35 Buckley et al. 2007).41Fresh-cut fruits respond to the demand for such healthy and easy products. Procedures such as cutting 42 and peeling expose the surface of the fruit to air and contaminants while also causing mechanical damage 43 to the cells which make the fruit more perishable (Ramos et al. 2013). As consumers tend to select fruit 44 products primarily based on their colour and appearance, fresh-cut fruits must indeed look fresh in order 45 to attract the attention of consumers (Barrett et al. 2010). Such delicate products require much from the 46 packaging. Studies conducted by Grönman et al. (2013) and Silvenius et al. (2014) have revealed that 47 the environmental impacts of the food are of a higher concern when compared to the product-packaging 48 system. Governments and customers have put much focus on the environmental impacts of the packaging 49 (Williams et al. 2008). 50Plastic production for packaging represents the largest application for plastic nowadays (Lagaron and 51 Lopez-Rubio 2010). In particular, petrochemical-based plastics have been increasingly used as packaging 52 materials because of their large availability at relatively low cost and because of their good mechanical 53

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This work reports on the design and development of nanocomposites based on a polymeric matrix containing biodegradable Polylactic Acid (PLA) and Polyhydroxyalkanoate (PHA) coated with either Graphite NanoPlatelets (GNP) or silver nanoparticles (AgNP). Nanocomposites were obtained by mechanical mixing under mild conditions and low load contents (<0.10 wt %). This favours physical adhesion of the additives onto the polymer surface, while the polymeric bulk matrix remains unaffected. Nanocomposite characterisation was performed via optical and focused ion beam microscopy, proving these nanocomposites are selectively modified only on the surface, leaving bulk polymer unaffected. Processability of these materials was proven by the fabrication of samples via injection moulding and mechanical characterisation. Nanocomposites showed enhanced Young modulus and yield strength, as well as better thermal properties when compared with the unmodified polymer. In the case of AgNP coated nanocomposites, the surface was found to be optically active, as observed in the increase of the resolution of Raman spectra, acquired at least 10 times, proving these nanocomposites are promising candidates as surface enhanced Raman spectroscopy (SERS) substrates.

On many occasions, sample treatment is a critical step in electrophoretic analysis. As an alternative to batch procedures, in this work, a new strategy is presented with a view to develop an on-capillary sample cleanup method. This strategy is based on the partial filling of the capillary with carboxylated single-walled carbon nanotube (c-SWNT). The nanoparticles retain interferences from the matrix allowing the determination and quantification of carbohydrates (viz glucose, maltose and fructose). The precision of the method for the analysis of real samples ranged from 5.3 to 6.4%. The proposed method was compared with a method based on a batch filtration of the juice sample through diatomaceous earth and further electrophoretic determination. This method was also validated in this work. The RSD for this other method ranged from 5.1 to 6%. The results obtained by both methods were statistically comparable demonstrating the accuracy of the proposed methods and their effectiveness. Electrophoretic separation of carbohydrates was achieved using 200 mM borate solution as a buffer at pH 9.5 and applying 15 kV. During separation, the capillary temperature was kept constant at 40 degrees C. For the on-capillary cleanup method, a solution containing 50 mg/L of c-SWNTs prepared in 300 mM borate solution at pH 9.5 was introduced for 60 s into the capillary just before sample introduction. For the electrophoretic analysis of samples cleaned in batch with diatomaceous earth, it is also recommended to introduce into the capillary, just before the sample, a 300 mM borate solution as it enhances the sensitivity and electrophoretic resolution.