Gaining the Freedom of Scalable Gas Diffusion Electrodes for the CO Reduction Reaction.

Gas diffusion electrodes (GDEs) in CO reduction reaction (CORR) alleviate the mass transfer limitation of gaseous reagents, which is beneficial for reducing CO into valuable chemicals. GDEs offer higher current densities compared to electrodes immersed in the electrolyte. Disclosing the roles of different structural parameters in tuning the performance of the GDEs is essential to exert the potential of catalysts and to meet potential large-scale industrial applications of the CORR.

Catalytic Biosensors Operating under Quasi-Equilibrium Conditions for Mitigating the Changes in Substrate Diffusion.

Despite the success of continuous glucose measuring systems operating through the skin for about 14 days, long-term implantable biosensors are facing challenges caused by the foreign-body reaction. We present a conceptually new strategy using catalytic enzyme-based biosensors based on a measuring sequence leading to minimum disturbance of the substrate equilibrium concentration by controlling the sensor between "on" and "off" state combined with short potentiometric data acquisition. It is required that the enzyme activity can be completely switched off and no parasitic side reactions allow substrate turnover.

Probing the local activity of CO reduction on gold gas diffusion electrodes: effect of the catalyst loading and CO pressure.

Large scale CO electrolysis can be achieved using gas diffusion electrodes (GDEs), and is an essential step towards broader implementation of carbon capture and utilization strategies. Different variables are known to affect the performance of GDEs. Especially regarding the catalyst loading, there are diverging trends reported in terms of activity and selectivity, for CO reduction to CO.

Scalable Fabrication of Biophotoelectrodes by Means of Automated Airbrush Spray-Coating.

The fabrication and electrochemical evaluation of transparent photoelectrodes consisting of Photosystem I (PSI) or Photosystem II (PSII) is described, which are embedded and electrically wired by a redox polymer. The fabrication process is performed by an automated airbrush-type spray coating system, which ensures controlled and scalable electrode preparation. As proof of concept, electrodes with a surface area of up to 25 cm were prepared.

Tuning Light-Driven Water Oxidation Efficiency of Molybdenum-Doped BiVO by Means of Multicomposite Catalysts Containing Nickel, Iron, and Chromium Oxides.

Mo-doped BiVO has emerged as a promising material for photoelectrodes for photoelectrochemical water splitting, however, still shows a limited efficiency for light-driven water oxidation. We present the influence of an oxygen-evolution catalyst composed of Ni, Fe, and Cr oxides on the activity of Mo:BiVO photoanodes. The photoanodes are prepared by spray-coating, enabling compositional and thickness gradients of the incorporated catalyst.

Optimized Ag Nanovoid Structures for Probing Electrocatalytic Carbon Dioxide Reduction Using Operando Surface-Enhanced Raman Spectroscopy.

Surface-enhanced Raman spectroscopy is a powerful analytical tool and a strongly surface structure-dependent process. Importantly, it can be coupled with electrochemistry to simultaneously record vibrational spectroscopic information during electrocatalytic reactions. Highest Raman enhancements are obtained using precisely tuned nanostructures.

Amperometric Detection of dsDNA using an Acridine-Orange-Modified Glucose Oxidase.

Invited for this month's cover is the group of Prof. Dr. Wolfgang Schuhmann, Dr.

Amperometric Detection of dsDNA Using an Acridine-Orange-Modified Glucose Oxidase.

In the present "genomic era" and in the developing world of DNA chips, DNA detection based on intercalation of specific molecules is of particular interest because the detection process is largely independent of the sequence of the target DNA. In this work, an acridine-orange-based intercalation compound, which was tethered to deglycosylated glucose oxidase was synthesized ad hoc and investigated for its ability to interact with dsDNA. Amperometric detection of DNA hybridization was achieved by signal amplification based on the catalytic oxidation of glucose by DNA-bound glucose oxidase.

Rechargeable, flexible and mediator-free biosupercapacitor based on transparent ITO nanoparticle modified electrodes acting in µM glucose containing buffers.

We present a transparent and flexible self-charging biosupercapacitor based on an optimised mediator- and membrane-free enzymatic glucose/oxygen biofuel cell. Indium tin oxide (ITO) nanoparticles were spray-coated on transparent conducting ITO supports resulting in a flocculent, porous and nanostructured electrode surface. By this, high capacitive currents caused by an increased electrochemical double layer as well as enhanced catalytic currents due to a higher number of immobilised enzyme molecules were obtained.

Transparent, mediator- and membrane-free enzymatic fuel cell based on nanostructured chemically modified indium tin oxide electrodes.

We detail a mediator- and membrane-free enzymatic glucose/oxygen biofuel cell based on transparent and nanostructured conducting supports. Chemically modified indium tin oxide nanoparticle modified electrodes were used to substantially increase the active surface area without significantly compromising transparency. Two different procedures for surface nanostructuring were employed, viz.