The development of upscalable oxygen evolving electrocatalysts from earth-abundant metals able to operate in neutral or acidic environments and low overpotentials remains a fundamental challenge for the realization of artificial photosynthesis. In this study, we report a highly active phase of heterobimetallic cyanide-bridged electrocatalysts able to promote water oxidation under neutral, basic (pH < 13), and acidic conditions (pH > 1). Cobalt–iron Prussian blue-type thin films, formed by chemical etching of Co­(OH)1.0(CO3)0.5·nH2O nanocrystals, yield a dramatic enhancement of the catalytic performance toward oxygen production, when compared with previous reports for analogous materials. Electrochemical, spectroscopic, and structural studies confirm the excellent performance, stability, and corrosion resistance, even when compared with state-of-the-art metal oxide catalysts under moderate overpotentials and in a remarkably large pH range, including acid media where most cost-effective water oxidation catalysts are not useful. The origin of the superior electrocatalytic activity toward water oxidation appears to be in the optimized interfacial matching between catalyst and electrode surface obtained through this fabrication method.

Hydrogen is a most desirable solar energy storage medium. It provides reliable, scalable, and long-term energy storage, while helping in the decarbonization of the energy cycle. Such a storage medium is required for further deployment of photovoltaics, either for their inclusion into transportation and heavy industries or for supporting renewable grid management. The most accessible hydrogen source is water. However, fresh water is a scarce resource, while seawater is abundant worldwide. A major drawback of seawater electrolysis comes from chloride oxidation competing with the oxygen evolution reaction (OER). This may produce toxic products such as chlorine and also limits the hydrogen energy efficiency of the overall process. Thus, selective catalysts toward the OER are of strong technological interest. Here we report the electrocatalytic activity of heterogeneous cobalt hexacyanoferrate toward seawater oxidation. Combining experimental and computational studies, we highlight the great difficulty in obtaining such selectivity and its main mechanistic descriptors. This Prussian blue derivative is an excellent and robust OER electrocatalyst, but unfortunately, it is not selective enough toward the OER in the presence of Cl– anions. Faradaic efficiencies above 30% toward Cl2 were observed during untreated seawater bulk electrolysis.

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A controlled, rapid, and potentiostat-free method has been developed for grafting the diazonium salt (3,5-bis(4-diazophenoxy)benzoic acid tetrafluoroborate (DCOOH)) on gold and carbon substrates, based on a Zn-mediated chemical dediazonation. The highly stable thin layer organic platforms obtained were characterized by cyclic voltammetry, AFM, impedance, XP, and Raman spectroscopies. A dediazonation mechanism based on radical formation is proposed. Finally, DCOOH was proved as a linker to an aminated electroactive probe.

Two fluorescent ligands, 3,5-dimethyl-4-(6'-sulfonylammonium-1'-azonaphthyl)pyrazole (dmpzn, 1) and 3,5-dimethyl-4-(4'-N,N'-dimethylaminoazophenyl)pyrazole (dmpza, 2) were obtained by condensation of ketoenolic derivatives with hydrazine. 1 and 2 formed the novel dinuclear complexes [(H(2)O)(3)ClRu(micro-L)(2)RuCl(H(2)O)(3)] (3 or 4) and [(H(2)O)(NO)Cl(2)Ru(micro-L)(2)RuCl(2)(NO)(H(2)O)] (6 or 7) (where L 1 = 2 or , respectively) which were characterized by IR, NMR and elemental analysis. The nitrosyl complexes were prepared by bubbling purified nitric oxide through methanol solutions of the corresponding ruthenium(II) chloroderivative or by reaction of the appropriate ligands with Ru(NO)Cl(3). Complexes 3 and 4 were found to bind NO, resulting in an increase in fluorescence. Ligand 1 also formed the mononuclear nitrosyl complex [Ru(NO)(bpy)(2)(dmpzn)]Cl(2) (8) which released NO in water at physiological pH and in the solid state as revealed by fluorescence and IR measurements, respectively.

In this paper, we describe the development of an enzyme-linked oligonucleotide assay for the detection of a human leukocyte antigen allele associated with celiac disease based on cyclodextrin-modified polymeric surfaces. The surface of maleimide-pre-coated plates was modified with a layer of thiolated cyclodextrin polymer and used for the supramolecular capture of adamantane or ferrocene-modified carboxymethylcellulose polymers bearing DNA probes. The assay was optimised in terms of incubation time, temperature, and surface chemistry and applied to the highly sensitive and selective detection of HLA sequences with a limit of detection of 0.7 nM. A real sample analysed using this platform showed an excellent correlation with maleimide-activated plates using thiolated DNA probes.

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