TL;DR: The major factors that play a role in the development of clinically accurate in-vivo glucose sensors include issues related to biocompatibility, miniaturization, long-term stability of the enzyme and transducer, oxygen deficit, short stabilization times, in- vivo calibration, baseline drift, safety, and convenience.
Abstract: First-generation glucose biosensors relied on the use of the natural oxygen cosubstrate and the production and detection of hydrogen peroxide and were much simpler, especially when miniaturized sensors are concerned. More sophisticated bioelectronic systems for enhancing the electrical response, based on patterned monolayer or multilayer assemblies and organized enzyme networks on solid electrodes, have been developed for contacting GOx with the electrode support. Electrochemical biosensors are well suited for satisfying the needs of personal (home) glucose testing, and the majority of personal blood glucose meters are based on disposable (screen-printed) enzyme electrode test strips, which are mass produced by the thick film (screen-printing) microfabrication technology. In the counter and an additional “baseline” working electrode, various membranes (mesh) are incorporated into the test strips along with surfactants, to provide a uniform sample coverage. Such devices offer considerable promise for obtaining the desired clinical information in a simpler, user-friendly, faster, and cheaper manner compared to traditional assays. Continuous ex-vivo monitoring of blood glucose was proposed in 1974 and the majority of glucose sensors used for in-vivo applications are based on the GOx-catalyzed oxidation of glucose by oxygen. The major factors that play a role in the development of clinically accurate in-vivo glucose sensors include issues related to biocompatibility, miniaturization, long-term stability of the enzyme and transducer, oxygen deficit, short stabilization times, in-vivo calibration, baseline drift, safety, and convenience.
TL;DR: In this article, the authors proposed a fabrication technique for dye-sensitized solar cells having a conversion efficiency of global air mass 1.5, 1000 W/m(2) solar light to electric power over 10%.
TL;DR: The achieved ultrahigh oxygen evolution activity and strong durability, with superior performance in comparison to the state-of-the-art noble-metal/transition-metal and nonmetal catalysts, originate from the unique nanowire array electrode configuration and in situ carbon incorporation, which lead to the large active surface area, enhanced mass/charge transport capability, easy release of oxygen gas bubbles, and strong structural stability.
Abstract: Hybrid porous nanowire arrays composed of strongly interacting Co3O4 and carbon were prepared by a facile carbonization of the metal–organic framework grown on Cu foil. The resulting material, possessing a high surface area of 251 m2 g–1 and a large carbon content of 52.1 wt %, can be directly used as the working electrode for oxygen evolution reaction without employing extra substrates or binders. This novel oxygen evolution electrode can smoothly operate in alkaline solutions (e.g., 0.1 and 1.0 M KOH), affording a low onset potential of 1.47 V (vs reversible hydrogen electrode) and a stable current density of 10.0 mA cm–2 at 1.52 V in 0.1 M KOH solution for at least 30 h, associated with a high Faradaic efficiency of 99.3%. The achieved ultrahigh oxygen evolution activity and strong durability, with superior performance in comparison to the state-of-the-art noble-metal/transition-metal and nonmetal catalysts, originate from the unique nanowire array electrode configuration and in situ carbon incorporati...
TL;DR: This study shows the successful integration of paper-based microfluidics and electrochemical detection as an easy-to-use, inexpensive, and portable alternative for point of care monitoring.
Abstract: We report the first demonstration of electrochemical detection for paper-based microfluidic devices. Photolithography was used to make microfluidic channels on filter paper, and screen-printing technology was used to fabricate electrodes on the paper-based microfluidic devices. Screen-printed electrodes on paper were characterized using cyclic voltammetry to demonstrate the basic electrochemical performance of the system. The utility of our devices was then demonstrated with the determination of glucose, lactate, and uric acid in biological samples using oxidase enzyme (glucose oxidase, lactate oxidase, and uricase, respectively) reactions. Oxidase enzyme reactions produce H2O2 while decomposing their respective substrates, and therefore a single electrode type is needed for detection of multiple species. Selectivity of the working electrode for H2O2 was improved using Prussian Blue as a redox mediator. The determination of glucose, lactate, and uric acid in control serum samples was performed using chron...
TL;DR: In this article, a method for the characterization of the electrocatalytic properties of highly dispersed electro catalysts in a true rotating disk electrode configuration by attaching the catalyst powder on a glossy carbon electrode via a thin Nafion film is presented.
Abstract: A newly developed method is presented which allows the characterization of the electrocatalytic properties of highly dispersed electrocatalysts in a true rotating disk electrode (RDE) configuration by attaching the catalyst powder on a glossy carbon electrode via a thin Nafion film. Complete utilization and high reproducibility of both the electrode preparation and the catalyst loading could be shown via voltammetry and CO stripping voltammetry. Furthermore RDE measurements on the electro‐oxidation of hydrogen on Pt/Vulcan showed that the effect of diffusion through the Nation film can be avoided by proper electrode preparation. Therefore, the electrode kinetics for fuel cell relevant reactions under continuous flow conditions can be measured directly without mathematical modeling.