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Electrochemical sensors to quantify concentrations of emerging pollutants have attracted great attention from the industry and scientific community. Nanomaterials such as carbon black have been applied in sensors to identify substances that are toxic to the environment and human health due to their excellent electroanalytical properties. The aim of the study was to develop a novel electrochemical sensor for the endocrine disruptor hormone determination. To our knowledge, for the first time the synthesis of material based on carbon black containing immobilized palladium nanoparticles, with the application for the hormone ethinylestradiol, is reported in the literature. The material was synthesized, characterized, and applied to the determination in tap water and human urine of the synthetic hormone 17α‐ethinylestradiol (EE2), which is currently considered an emerging pollutant. The morphology, structure and electrochemical performance of the sensors were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Differential pulse voltammetry (DPV) in sodium phosphate buffer solution at pH 5.0 allowed the generation of a method to quantify the concentration of 17α‐ethinylestradiol in a linear range of 0.5–119.0 μmol L−1, obtaining 81.0 nmol L−1 of calculated limit of detection (LOD). The system was efficient in detecting 17α‐ethinylestradiol in real urine samples and showed no interferences for ascorbic acid, uric acid, progesterone, and dopamine. It is noteworthy that the results obtained showed good recovery values, considering that the urine samples were not previously treated or pre‐concentrated, which suggests the development of an electrochemical sensor that works in situ and in real time to monitor relevant substances in the control clinical and environmental, with the possibility of point‐of‐care analyses. [ABSTRACT FROM AUTHOR]

The paper reports the development of a new sensor based on Printex L6 (CPL6) carbon black modified with copper oxides (CuO/Cu2O) nanoparticles and its application towards the determination of Propylparaben (PP). In fact, it is the first report of its kind in the literature. The sensor was produced through the dispersion of CPL6 in dimethylformamide on glassy carbon electrode surface followed by CuO/Cu2O electrodeposition. The conditions of electrodeposition investigated included time and solution concentration of Cu (II). Morphological, structural and electrochemical characterizations of the sensor were performed. Under optimal conditions, wide linear range (1.0 to 35.0 μmol L−1) was obtained in the detection of PP. The detection limit obtained was 0.46 μmol L−1 (S/N=3). The CuO/Cu2O‐CPL6/GCE sensor was found to be as sensitive as the high performance liquid chromatography in the determination of PP in both cosmetic and river water samples, in addition to being reproducible and stable. [ABSTRACT FROM AUTHOR]

In this work, a simple and highly selective voltammetric method was developed for the simultaneous determination of paracetamol (PCT) and codeine (COD) in pharmaceuticals and human body fluids employing a glassy carbon electrode modified with carbon black (CB) and nickel oxide nanoparticles (NiONPs) within a dihexadecylphosphate (DHP) film. Using square-wave voltammetry (SWV), a separation of ca. 550 mV between the oxidation peak potentials of PCT and COD was obtained. The simultaneous determination of PCT and COD presented a linear concentration range from 3.0 to 47.8 µmol L−1 for PCT and from 0.83 to 38.3 µmol L−1 for COD. [ABSTRACT FROM AUTHOR]

An 'abiotic' biofuel cell composed of catalytic electrodes modified with inorganic nanoparticles (NPs) deposited on carbon black (CB) was used to activate a wireless information transmission system. The cathode and anode were made of carbon paper modified with Pt-NPs/CB and buckypaper modified with Au80Pt20-NPs/CB, respectively. The cathode/anode pair was implanted in orange pulp extracting power from its content (glucose and fructose in the juice). The open circuit voltage, Voc, short circuit current density, jsc, and maximum power produced by the biofuel cell, Pmax, were found as 0.36 V, 1.3 mA cm−2 and 182 µW, respectively. The voltage produced by the biofuel cell was amplified with an energy harvesting circuit and applied to a wireless transmitter. The present study continues the research line where different implantable biofuel cells are used for activation of electronic devices. [ABSTRACT FROM AUTHOR]

An 'abiotic' biofuel cell composed of catalytic electrodes modified with inorganic nanostructured species was used to activate a pacemaker. The catalytic nanoparticles of various compositions, Au xPt y, deposited on carbon black (CB) were prepared and extensively characterized to select the species with selectivity for glucose oxidation and oxygen reduction. Then two kinds of 3D-electrode materials with different morphology, buckypaper composed of carbon nanotubes (ca. 50 nm diameter) and carbon paper made of carbon fibers (ca. 7 µm diameter), were used in a combination with different catalytic species. Finally, Au/CB nanospecies deposited on buckypaper were selected for catalyzing glucose oxidation (composing the biofuel cell anode) and Au60Pt40/CB species deposited on carbon paper were selected for catalyzing oxygen reduction (composing the biofuel cell cathode). The catalytic electrodes were characterized by cyclic voltammetry in an aqueous buffer solution and the polarization function for the biofuel cell was studied in a human serum solution. The open circuit voltage, Voc, short circuit current density, jsc, and maximum power produced by the biofuel cell, Pma x, were found as 0.35 V, 0.65 mA cm−2 and 104 µW, respectively (in human serum at 5.4 mM glucose). The biofuel cell produced the steady state open circuit voltage over 10 hours with its slow decrease over 50 hours originating from the glucose depletion and slow mass-transport within the 3D-electrode. The voltage produced by the biofuel cell was amplified with an energy harvesting circuit and applied to a pacemaker resulting in its proper operation. The present study continues the research line where different implantable (enzyme-based or abiotic) biofuel cells are used for the activation of biomedical electronic devices, e.g., pacemakers. [ABSTRACT FROM AUTHOR]