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In this work, Coca-Cola® bottles were reused as a PET polymer (rPET) source to produce electrospun polymeric nanofibers. The nanofibers were electrospun from polymer solutions with different concentrations of reduced graphene oxide (rGO) incorporated for applications in somatosensory electrical stimulation. The rPET/rGO nanofiber mats were characterized by SEM, TEM, Raman, DSC, TGA, and DMA and the results showed that the incorporation of rGO in electrospun rPET fibers produced rPET/rGO composites. The rPET/rGO composites were then evaluated for possible application as dry electrodes. Moreover, with a preliminary test of numerous volunteers, the rPET/rGO dry electrode showed promising results. The rPET/rGO electrodes showed good performance and applicability to make dry electrodes, and these have applications as dry or wearable electrodes to produce electrochemical sensors.

The search for new nanostructured materials that have an antimicrobial activity and which may arise as an alternative in biotechnological applications has aroused great interest by the scientific community. The use of natural resources in the development of these materials becomes interesting not only because of their availability and low cost, but also because they are materials with low or no toxicity and properties of interest, such as palygorskite clay ( PAL), also called atapulgite. Thus, a new applicability is proposed with the use of this natural resource for the development of biotechnological products, such as the development of nanocomposites constituted by the incorporation of silver nanoparticles (AgNPs) in PAL for its use as bactericidal agent. The objective of the research was to carry out a prospective study on the basis of periodicals of Scopus, Web of Science and Scielo, as well as in the patent banks of the National Institute of Industrial Property (INPI), European Patent Office (Espacenet) and United States Patent and Trademark Offic (USPTO), from 2006 to 02/2017. From the results of articles and patents, a considerable number of articles and patents were found using the word "Palygorskite" or "Attapulgite". However, when the "Palygorskite or Attapulgite AND silver nanoparticle AND antimicrobial" and "Palygorskite or Attapulgite AND silver nanoparticle AND bactericidal" combinations were used, no article or patent has been found to date. Thus, the development of PAL / AgNPs nanocomposites for biotechnological applications can be very promising and innovative for the characteristics presented by both materials. Keywords: Nanocomposites; Palygorskite; Attapulgite; Silver of nanoparticles; Bactericidal agent.

Nanocomposite materials have been proposed to enhance the properties of different materials. In this study, palygorskite (Pal) clay is proposed as a support matrix for silver nanoparticles stabilised with cashew gum (Anacardium occidentale L.) (AgNPs-CG), producing the Pal/AgNPs-CG nanocomposite, whose bactericidal activity was studied. AgNPs-CG was synthesised using a green method in which CG acted as a reducing and stabilising agent for these nanostructures. AgNPs-CGs were subsequently characterised then adsorbed to the Pal surface, which was previously treated to remove impurities such as quartz. Pal and Pal/AgNPs-CG were characterised by X-ray diffraction, specific surface area, thermal analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and transmission electron microscopy. The antibacterial activity assay by the direct contact method showed that the synergistic effect of the combination of AgNPs-CG and Pal increased the bactericidal effect of the nanomaterial compared with the AgNPs-CG activity, reaching a percentage inhibition of up to 70.2% against E. coli and 85.3% against S. aureus. Nanocomposite atoxicity was demonstrated by the Artemia Salina model. Thus, the Pal/AgNPs-CG nanocomposite emerges as a nanomaterial with potential antibacterial applications.