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In this work a comparative study of Screen‐Printed Carbon Electrodes (SPCE) – bare and modified by drop casting with carbonaceous nanomaterials (CNMs) as Multi Walled Carbon Nanotubes (MWCNT), Carbon Black and Functionalized Carbon Black for voltammetric determination of 5‐methyl‐6‐nitro‐7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidinide l‐arginine monohydrate (Triazid) as a potential drug with a broad spectrum of antiviral activity is reported. Bare SPCE and CNMs modified SPCE (SPCE/CNMs) have been characterized morphologically by SEM and electrochemically by cyclic voltammetry/electrochemical impedance spectroscopy with [Fe(CN)6]4−/3− as redox probe. Significant improvement of electrochemical performances is achieved with SPCE/CNMs compared with the bare SPCE. Among SPCE/CNMs studied SPCE modified with MWCNT (SPCE/CNT) is characterized by the best combination of electrochemical properties and electroanalytical performance towards TD. The linear dynamic range is 25–200 mg L−1 (R2=0.9975) with the limit of detection – 2.8 mg L−1 Triazid using SPCE/CNT and Square‐Wave Voltammetry technique. The developed sensor was successfully used for Triazid determination in the Pharmaceutical Substance "TRIAZID". The results achieved with SPCE/CNMs after chemical binding of dissolved oxygen in 0.04 M Britton‐Robinson buffer+0.04 M Na2SO3 (pH 7.2±0.2) are very useful for further development of cost‐effective and time‐consuming pharmaceutical routine assay. [ABSTRACT FROM AUTHOR]

In this work a comparative study using Screen-Printed Electrodes (SPEs) modified by drop casting with Carbon Black, Single Walled Carbon NanotubesCOOH, Graphene Oxide, and reduced Graphene Oxide is reported. The carbon nanomaterials employed were characterized by X-ray photoelectron and Raman spectroscopy, while the modified SPEs have been morphologically and electrochemically characterized. Nanoengineered SPEs have been tested with ferricyanide, NADH, ascorbic acid and cysteine. We observed valuable electroanalytical performances of Carbon Black with the advantage to be i) cost-effective ii) suitable to obtain stable and homogenous dispersion and iii) mass-producible following a well established route. [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]