Nitrate reductase (NR) from the plant Arabidopsis thaliana has been employed in the development of an amperometric nitrate biosensor that functions at physiological pH. The anion anthraquinone-2-sulfonate (AQ) is used as an effective artificial electron transfer partner for NR at a glassy carbon (GC) electrode. Nitrate is enzymatically reduced to nitrite and the oxidized form of NR is electrochemically reduced by the hydroquinone form of the mediator (AQH2). The GC/NR electrode shows a pronounced cathodic wave for nitrate reduction and the catalytic current increases linearly in the nitrate concentration range of 10-400 µM with a correlation coefficient of 0.989. Using an amperometric method, a low detection limit of 0.76 nM (S/N = 3) was achieved. The practical application of the present electrochemical biosensor was demonstrated by the determination of nitrate concentration in natural water samples and the results agreed well with a standard spectroscopic method.
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http://dx.doi.org/10.1007/s00775-014-1171-0 | DOI Listing |
Nat Commun
December 2024
School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Electrochemical nitrate reduction reaction offers a sustainable and efficient pathway for ammonia synthesis. Maintaining satisfactory Faradaic efficiency for long-term nitrate reduction under ampere-level current density remains challenging due to the inevitable hydrogen evolution, particularly in pure nitrate solutions. Herein, we present the application of electron deficiency of Ru metals to boost the repelling effect of counter K ions via the electric-field-dependent synergy of interfacial water and cations, and thus largely promote nitrate reduction reaction with a high yield and well-maintained Faradaic efficiency under ampere-level current density.
View Article and Find Full Text PDFNat Commun
December 2024
School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China.
Fine particulate matter has been linked with acute coronary syndrome. Nevertheless, the key constituents remain unclear. Here, we conduct a nationwide case-crossover study in China during 2015-2021 to quantify the associations between fine particulate matter constituents (organic matter, black carbon, nitrate, sulfate, and ammonium) and acute coronary syndrome, and to identify the critical contributors.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
State Key Laboratory of Electrical Insulation and Power Equipment, Centre for Plasma Biomedicine, Xi'an Jiaotong University, Xi'an, 710049, P. R. China.
Liquid fertilizers, particularly when integrated with precision irrigation systems, offer a more efficient and sustainable alternative to traditional solid nitrogen fertilizers. The industrial production of ammonium nitrate (NHNO) is environmentally detrimental due to its reliance on fossil fuels. This study introduces an innovative air-to-NOx-to-NHNO pathway for synthesizing liquid nitrogen fertilizer.
View Article and Find Full Text PDFJ Integr Plant Biol
December 2024
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education; Shandong Key Laboratory of Precision Molecular Crop Design and Breeding; School of Life Sciences, Shandong University, Qingdao, 266237, China.
Nitrate not only serves as the primary nitrogen source for terrestrial plants but also serves as a critical signal in regulating plant growth and development. Understanding how plant responses to nitrate availability is essential for improving nitrogen use efficiency in crops. Herein, we demonstrated that the basic helix-loop-helix (bHLH) transcription factor TabHLH489 plays a crucial negative regulatory role in wheat nitrate signaling.
View Article and Find Full Text PDFFront Chem
December 2024
Department of Chemistry, Cleveland State University, Cleveland, OH, United States.
Quenching peroxynitrite (a reactive oxidant species) is a vital process in biological systems and environmental chemistry as it maintains redox balance and mitigates damaging effects in living cells and the environment. In this study, we report a systematic analysis of the mechanism of transforming peroxynitrite into nitrate using diaryl selenide in water. Through quantum mechanical calculations, we investigate the dynamic isomerization of peroxynitrite in a homogeneous catalytic environment.
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