Publications by authors named "Cristian M Moreira"

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).

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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.

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Introduction: The PKU is an inborn error of amino acid metabolism, in which phenylalanine (Phe) accumulated in the blood causing alterations at the central nervous system. We report a novel paper-based enzymatic platform coupled to screen printed graphene-modified electrode for the neonatal screening of phenylketonuria (PKU0.

Methods: The paper-based analytical device coupled to electrochemical detection (EPAD) is based on the use of paper microzones modified with phenylalanine dehydrogenase enzyme (PheDH).

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