Direct electron transfer between redox enzymes and electrodes is the basis for the third generation biosensors. We established direct electron transfer between quinohemoprotein alcohol dehydrogenase (PQQ-ADH) and modified carbon black (CBs) electrodes. Furthermore, for the first time, this phenomenon was observed for pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase (PQQ-GDH). Reagentless enzyme biosensors suitable for the determination of ethanol, glucose and sensors for hydrogen peroxide were designed using CB electrodes and screen-printing technique. Aiming to create an optimal transducing material for biosensors, a set of CB batches was synthesized using the matrix of Plackett-Burman experimental design. Depending on the obtained surface functional groups as well as the nano-scale carbon structures in CBs batches, the maximal direct electron transfer current of glucose and ethanol biosensors can vary from 20 to 300 nA and from 30 to 6300 nA for glucose and ethanol, respectively. Using modified CB electrodes, an electrocatalytic oxidation of H(2)O(2) takes place at more negative potentials (0.1-0.4V versus Ag/AgCl). Moreover, H(2)O(2) oxidation efficiency depends on the amount and morphology of fine fraction in the modified CBs.
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http://dx.doi.org/10.1016/j.talanta.2005.04.004 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Research Centre for Energy, Environment and Technology (CIEMAT), Avda. Complutense, 40, 28040, Madrid, Spain.
As tailpipe emissions have decreased, there is a growing focus on the relative contribution of non-exhaust sources of vehicle emissions. Addressing these emissions is key to better evaluating and reducing vehicles' impact on air quality and public health. Tailoring solutions for different non-exhaust sources, including brake emissions, is essential for achieving sustainable mobility.
View Article and Find Full Text PDFNano Converg
January 2025
Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea.
Two-dimensional halide perovskites are attracting attention due to their structural diversity, improved stability, and enhanced quantum efficiency compared to their three-dimensional counterparts. In particular, Dion-Jacobson (DJ) phase perovskites exhibit superior structural stability compared to Ruddlesden-Popper phase perovskites. The inherent quantum well structure of layered perovskites leads to highly anisotropic charge transport and optical properties.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia; Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic. Electronic address:
Tire wear microplastics (TWMs) are continuously generated during driving and are subsequently released into the environment, where they pose potential risks to aquatic organisms. In this study, the effects of untreated, hydrated, and environmentally aged TWMs on the growth, root development, photosynthesis, electron transport system (ETS) activity, and energy-rich molecules of duckweed Lemna minor were investigated. The results indicated that untreated and aged TWMs have the most pronounced negative effects on Lemna minor, as evidenced by reduced growth and impaired root development.
View Article and Find Full Text PDFRep Prog Phys
January 2025
Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus, Midtjylland, 8000, DENMARK.
Irradiation of condensed matter with ionizing radiation generally causes direct photoionization as well as secondary processes that often dominate the ionization dynamics. Here, large helium (He) nanodroplets with radius ≳ 40 nm doped with lithium (Li) atoms are irradiated with extreme ultraviolet (XUV) photons of energy hν ≥ 44.4 eV and indirect ionization of the Li dopants is observed in addition to direct photoionization of the He droplets.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Electronics Sciences and Technology Division, United States Naval Research Laboratory, Washington, DC 20375.
This study presents the direct measurement of proton transport along filamentous , or cable bacteria. Cable bacteria are filamentous multicellular microorganisms that have garnered much interest due to their ability to serve as electrical conduits, transferring electrons over several millimeters. Our results indicate that cable bacteria can also function as protonic conduits because they contain proton wires that transport protons at distances >100 µm.
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