Publications by authors named "Anderson M Santos"

This study reports the development and implementation of a straightforward, rapid, and cost-effective voltammetric technique for piroxicam (PIR) detection at nanomolar concentrations in biological and environmental samples. The method involved the use of a screen-printed electrode (SPE) enhanced with a combination of Printex L6 carbon (PL6C) and polyaniline-based activated carbon (PAC) on a chitosan film crosslinked with epichlorohydrin (CTS:EPH). The detection was carried out using square-wave adsorptive anodic stripping voltammetry (SWAdASV) in a 0.

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Nifedipine, a widely utilized medication, plays a crucial role in managing blood pressure in humans. Due to its global prevalence and extensive usage, close monitoring is necessary to address this widespread concern effectively. Therefore, the development of an electrochemical sensor based on a glassy carbon electrode modified with carbon nanofibers and gold nanoparticles in a Nafion film was performed, resulting in an active electrode surface for oxidation of the nifedipine molecule.

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Article Synopsis
  • The study presents a new flow injection analysis (FIA) system for measuring uric acid (UA) and caffeine (CAF) simultaneously, utilizing a cathodically pretreated boron-doped diamond electrode (CPT-BDD) with multiple-pulse amperometry (MPA).
  • Under specific optimized conditions, two distinct oxidation peaks were identified for UA and CAF, allowing for accurate concentration measurements with low detection limits.
  • The method showed high reliability, stability, and resistance to interference from common substances in environmental samples, achieving recovery rates between 98% and 104%.
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This work reports the development and application of a simple, rapid and low-cost voltammetric method for the determination of 3-methylmorphine at nanomolar levels in clinical and environmental samples. The proposed method involves the combined application of a glassy carbon electrode modified with reduced graphene oxide, chitosan and bismuth film (Bi-rGO-CTS/GCE) via square-wave voltammetry using 0.04 mol L Britton-Robinson buffer solution (pH 4.

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A new electrode was prepared based on functionalized graphene and gold nanoparticles dispersed in a chitosan film. Such an electrochemical sensor determines ofloxacin in the presence of dopamine, paracetamol, and caffeine. Characterization (morphological and electrochemical) was done using scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry.

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This paper reports the development of a voltammetric sensor using glassy carbon electrode based on hierarchical porous carbon (HPC) with silver sulfide nanoparticles (AgSNP), Nafion and fullerene (C) for the determination of nitrite in foods. Raman spectroscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray were used to characterize the morphology and composition of the materials. The use of HPC and C in the construction of the electrode contributed toward the enlargement of the specific surface area and the improvement of the electrochemical performance of the device.

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Article Synopsis
  • A new method for detecting ethinylestradiol was developed using a specialized screen-printed electrode (SPE) modified with functionalized graphene, graphene quantum dots, and magnetic nanoparticles with molecularly imprinted polymers (mag@MIP).
  • Performance comparisons showed that the mag@MIP sensor outperformed a non-molecularly imprinted sensor (mag@NIP), with a significant increase in electrochemical response measured through cyclic voltammetry.
  • The mag@MIP sensor demonstrated high sensitivity, with a detection limit of 2.6 nmol L, and effectively identified ethinylestradiol in various samples, achieving recovery rates of 96-105% for environmental and 97-104% for biological samples.
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The present study reports the development of graphite pencil electrode modified with palladium nanoparticles (PdNPs) and its application as an electrochemical sensor for the simultaneous detection of direct yellow 50, tryptophan, carbendazim and caffeine in river water and synthetic urine samples. The combination involving the conductive surface of the graphite pencil electrode (GPE) and the enlargement of the surface area caused by the use of palladium nanoparticles (PdNPs) led to the improvement of the analytical performance of the proposed device. The surface of the GPE-PdNPs was characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).

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A new electrochemical device based on a combination of nanomaterials such as Printex 6L Carbon and cadmium telluride quantum dots within a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate film was developed for sensitive determination of amoxicillin. The morphological, structural and electrochemical characteristics of the nanostructured material were evaluated using X-ray diffraction, confocal microscopy, transmission electron microscopy and voltammetric techniques. The synergy between these materials increased the electrochemical activity, the electron transfer rate and the electrode surface area, leading to a high magnitude of the anodic peak current for the determination of amoxicillin.

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A composite electrode based on graphite oxide (GrO)-polyurethane (PU) modified with β-cyclodextrin (CD) was proposed for the simultaneous determination of three drugs: terbutaline (TER), nimesulide (NIM), and methocarbamol (MET), as possible contaminants in river water samples. To evaluate the performance of the proposed CD-GrOPUE, voltammetric techniques were used and two other electrodes were fabricated (GrOPUE and GrPUE) for comparison. The functionalization of the GrO was confirmed by scanning electron microscopy images, energy-dispersive X-ray spectroscopy analysis, and thermogravimetry.

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A carbon paste electrode (CPE) was modified with graphite oxide (GrO) and β-cyclodextrin (CD) to obtain a sensor for simultaneous voltammetric determination of levodopa (LD), piroxicam (PRX), ofloxacin (OFX) and methocarbamol (MCB). The morphology, structure and electrochemical properties of the functionalized GrO were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, contact angle measurements and cyclic voltammetry. Under the optimal experimental conditions, the sensor is capable of detecting LD, PRX, OFX and MCB by square wave voltammetry (SWV) at working potentials of +0.

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A glassy carbon electrode was modified with carbon black and CdTe quantum dots in a chitosan film to obtained a sensor for norfloxacin (NOR) in the presence of dopamine, caffeine, and uric acid. The morphological, structural and electrochemical characteristics of the nanostructured material were evaluated using spectrophotometry, X-ray diffraction, transmission electronic microscopy and voltammetry. The high electrochemical activity, fast electron transfer rate and high surface area enhanced the oxidation peak currents and shifted the peak potentials of NOR for more negative values (typically at 0.

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Article Synopsis
  • The study focused on using carbon black, graphene oxide, copper nanoparticles, and PEDOT:PSS as electrode materials for detecting multiple substances simultaneously, including isoproterenol and caffeine.
  • The surface of the electrodes was thoroughly characterized using techniques like SEM and EDS, revealing fast electron transfer and a large electroactive area.
  • Square-wave voltammetry was used to successfully identify and quantify these compounds in urine and serum, demonstrating the sensor's effectiveness with high recovery rates close to 100%.
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Tobacco has been identified as the drug with the highest addiction rate and the leading cause of avoidable deaths. The current study thus aimed to identify the determinants of smoking cessation in a Brazilian population sample based on data from the National Household Sample Survey for 2008. The study analyzed socioeconomic, residential, and health-related data as well as individual habits.

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