Modification of electrodes with polymer nanocomposites: Application to the simultaneous determination of Zn(II), Cd(II), and Cu(II) in water samples.

Currently, there is a need for fast and sensitive analytical methods for monitoring metals in water due to the progressive increase in the presence of metal ions in the environment. These metals reach the environment mainly from industrial activity and heavy metals are non-biodegradable. The present work evaluates different polymeric nanocomposites to carry out the simultaneous electrochemical determination of Cu, Cd, and Zn in water samples.

Novel solid inks based on beeswax, graphite and graphene applied to the fabrication of paper-based sensor for galactose determination.

In this study, we present for the first time a simple and novel method for the fabrication of paper-based electrochemical sensors. The device development was carried out in a single stage with a standard wax printer. Hydrophobic zones were delimited with commercial solid ink, while electrodes were generated using new composite solid inks of graphene oxide/graphite/beeswax (GO/GRA/beeswax) and graphite/beeswax (GRA/beeswax).

Paper surface modification strategies employing N-SBA-15/polymer composites in bioanalytical sensor design.

In this work, different paper surface modification strategies were compared to obtain an amine functionalized SBA-15 (N-SBA-15) composite for paper-based device development. The synthesized N-SBA-15 was characterized by N adsorption-desorption isotherm, and infrared spectroscopy (FTIR), and it was incorporated to different polymer matrices (κ-carrageenan (CA), polyvinyl alcohol (PVA) and polyethylenimine (PEI)) for the development of the composite modified paper-based device. The retention, interactions, and morphology of the obtained composites were investigated by absorbance measurement, FTIR and scanning electron microscopy (SEM), respectively.

Novel electrochemical sensing platform based on a nanocomposite of PVA/PVP/RGO applied to IgG anti- Toxoplasma gondii antibodies quantitation.

This article describes the development of a new electrochemical platform composed by a polymer mixture and graphene oxide (GO). The working electrode of a screen-printed carbon electrode (SPCE) was modified with nanocomposite constituted by poly-vinyl alcohol (PVA), poly-vinylpyrrolidone (PVP) and GO, which was electrochemically reduced to obtain PVA/PVP/RGO/SPCE. The interactions and morphology of the PVA/PVP/GO nanocomposite were investigated by SEM, FTIR and UV-Vis.

About endothermic sorption of tyrosine on chitosan films.

Sorption of l- and d-Tyrosine (Tyr) from aqueous solutions on chiral membranes of chitosan (CH) was studied. A high adsorption in the membrane, with a marked enantioselectivity to l-Tyr, was found. Computational calculations carried out by docking and molecular dynamics (MD) showed a difference in the affinity of the enantiomers and two regions of adsorption in the polymer matrix.