Cyclodextrin polymer clean-up method for the detection of ciguatoxins in fish with cell-based assays.

Ciguatoxins (CTXs) are marine toxins produced by microalgae of the genera Gambierdiscus and Fukuyoa, which are transferred through the food webs, reaching humans and causing a poisoning known as ciguatera. The cell-based assay (CBA) is commonly used for their detection because of its high sensitivity and the provided toxicological information. However, matrix effects may interfere in the CBA.

Cyclodextrin polymers as passive sampling materials for lipophilic marine toxins in Prorocentrum lima cultures and a Dinophysis sacculus bloom in the NW Mediterranean Sea.

Cyclodextrins, cyclic oligomers that form a conical structure with an internal cavity, are proposed as new and sustainable materials for passive sampling of lipophilic marine toxins. Two applicability scenarios have been tested. First, disks containing β-cyclodextrin-hexamethylene diisocyanate (β-CD-HDI) and β-cyclodextrin-epichlorohydrin (β-CD-EPI) polymers were immersed in Prorocentrum lima cultures for different days (2, 12 and 40).

Enhanced Activity and Acid pH Stability of Prussian Blue-type Oxygen Evolution Electrocatalysts Processed by Chemical Etching.

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)(CO)·nHO nanocrystals, yield a dramatic enhancement of the catalytic performance toward oxygen production, when compared with previous reports for analogous materials.

Electrochemiluminescent DNA sensor based on controlled Zn-mediated grafting of diazonium precursors.

Controlled Zn-mediated grafting of a thin layer of a diazonium salt was used to functionalise a carbon electrode with ruthenium(II)-tris-bipyridine (Ru)-labelled DNA for use as a capture probe in an electrochemiluminescent genosensor. A secondary reporter probe was labelled with a ferrocene (Fc) molecule, and in the presence of the single-stranded DNA target a genocomplex formed, where the Fc-label effectively quenched the electrochemiluminescence of the signal emitted from the Ru-label. The spacing of the labels for maximum sensitivity and minimum detection limit was optimised, and the signal reproducibility and stability of the method was established.

Controlled Zn-mediated grafting of thin layers of bipodal diazonium salt on gold and carbon substrates.

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.

Highly sensitive colorimetric enzyme-linked oligonucleotide assay based on cyclodextrin-modified polymeric surfaces.

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.

Nitric oxide binding and photodelivery based on ruthenium(II) complexes of 4-arylazo-3,5-dimethylpyrazole.

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).