307 research outputs found
Molecular electrocatalysis at soft interfaces
The fundamental aspects of electrochemistry at liquidâliquid interfaces are introduced to present the concept of molecular electrocatalysis. Here, a molecular catalyst is adsorbed at the interface to promote a proton coupled electron transfer reaction such as hydrogen evolution or oxygen reduction using lipophilic electron donors
Component-resolved diagnostic of cowâs milk allergy by immunoaffinity capillary electrophoresis â matrix assisted laser desorption/ionization mass spectrometry
Component-resolved diagnostic (CRD) of cowâs milk allergy has been performed using immunoaffinity capillary electrophoresis (IACE) coupled with matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). First, total IgE quantification in the blood serum of a milk allergic patient by IACE-UV technique was developed using magnetic beads (MBs) coated with anti-human IgE antibodies (Abs) to perform the general allergy diagnosis. Then, the immunocomplex of anti-human IgE Abs with the patient IgE Abs, obtained during the total IgE analysis, was chemically cross-linked on the MBs surface. Prepared immunosupport was used for the binding of individual milk allergens to identify the proteins triggering the allergy by IACE with UV and MALDI MS detection. Then, allergy CRD was also performed directly with milk fractions. Bovine serum albumin, lactoferrin and α-casein (S1 and S2 forms, as was revealed by MALDI MS) were found to bind with the extracted IgE Abs, indicating that the chosen patient is allergic to these proteins. The results were confirmed by performing classical enzyme-linked immunosorbent assay of total and specific IgE Abs. The present IACE-UV/MALDI MS method required only 2 ÎŒl of blood serum and allowed the performance of the total IgE quantification and CRD of the food allergy not only with the purified allergen molecules, but also directly with the food extract. Such an approach opens the possibility for direct identification of allergens molecular mass and structure, discovery of unusual allergens, which could be useful for precise personalized allergy diagnostic, allergens epitope mapping and cross-reactivity studies
Bioanalytical methods for food allergy diagnosis, allergen detection and new allergen discovery
For effective monitoring and prevention of the food allergy, one of the emerging health problems nowadays, existing diagnostic procedures and allergen detection techniques are constantly improved. Meanwhile, new methods are also developed, and more and more putative allergens are discovered. This review describes traditional methods and summarizes recent advances in the fast evolving field of the in vitro food allergy diagnosis, allergen detection in food products and discovery of the new allergenic molecules. A special attention is paid to the new diagnostic methods under laboratory development like various immuno- and aptamer-based assays, including immunoaffinity capillary electrophoresis. The latter technique shows the importance of MS application not only for the allergen detection but also for the allergy diagnosis
Scan-Rate-Dependent Ion Current Rectification and Rectification Inversion in Charged Conical Nanopores
Herein we report a theoretical study of diode-like behavior of negatively charged (e.g., glass or silica) nanopores at different potential scan rates (1-1000 V center dot s(-1)). Finite element simulations were used to determine current-voltage characteristics of conical nanop ores at various electrolyte concentrations. This study demonstrates that significant changes in rectification behavior can be observed at high scan rates because the mass transport of ionic species appears sluggish on the time scale of the voltage scan. In particular, it explains the influence of the potential scan rate on the nanopore rectifying properties in the cases of classical rectification, rectification inversion, and the "transition" rectification domain where the rectification direction in the nanopore could be modulated according to the applied scan rate
Effect of the Phase Volume Ratio on the Potential of a Liquid-Membrane Ion-Selective Electrode
Oxygen reduction at soft interfaces catalyzed by in situ-generated reduced graphene oxide
peer-reviewedFace to face: Flakes of reduced graphene oxide, synthesizedâ
in situ at the liquid/liquid interface from a grapheneâoxide precursor, are capable of catalyzing the biphasic reduction of protons to hydrogen peroxide in the presence of molecular oxygen and an organic solubilized electron donor. This offers a new perspective for the bulk production of a green oxidant through biphasic electrolysisACCEPTEDpeer-reviewe
Nanomaterial-assisted laser desorption ionization for mass spectrometry-based biomedical analysis
Nanomaterials have been widely used to assist laser desorption ionization of biomolecules for mass spectrometry analysis. Compared with classical matrix-assisted laser desorption ionization, strategies based on nanomaterial-assisted ionization generate a clean background, which is of great benefit for the qualitative and quantitative analysis of small biomolecules, such as therapeutic and diagnostic molecules. As label-free platforms, they have successfully been used for high-throughput enzyme activity/inhibition monitoring and also for tissue imaging to map in situ the distribution of peptides, metabolites and drugs. In addition to widely used porous silicon nanomaterials, gold nanoparticles can be easily chemically modified by thiol-containing compounds, opening novel interesting perspectives. Such functionalized nanoparticles have been used both as probes to extract target molecules and as matrices to assist laser desorption ionization for developing new enzyme immunoassays or for studying DNA hybridization. More recently, semiconductor nanomaterials or quantum dots acting as photosensitive centers to induce insource redox reactions for proteomics and to investigate biomolecule oxidation for metabolomics have been shown to offer new analytical strategies
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