Photocatalytic proton reduction is a promising way to produce dihydrogen (H-2) in a clean and sustainable manner, and mimicking nature by immobilising proton reduction catalysts and... Show morePhotocatalytic proton reduction is a promising way to produce dihydrogen (H-2) in a clean and sustainable manner, and mimicking nature by immobilising proton reduction catalysts and photosensitisers on liposomes is an attractive approach for biomimetic solar fuel production in aqueous solvents. Current photocatalytic proton reduction systems on liposomes are, however, limited by the stability of the catalyst. To overcome this problem, a new alkylated cobalt(II) polypyridyl complex (CoC12) was synthesised and immobilised on the lipid bilayer of liposomes, and its performance was studied in a photocatalytic system containing an alkylated ruthenium photosensitiser (RuC12) and a 1 : 1 mixture of sodium ascorbate and tris-2-carboxyethylphosphine hydrochloride as sacrificial electron donors. Several parameters (concentration of CoC12 and RuC12, pH, membrane composition) were changed to optimise the turnover number for H-2 production. Overall, CoC12 was found to be photostable and the optimised turnover number (161) was limited only by the decomposition of the ruthenium-based photosensitiser. Show less
Zurlo, E.; Passerini, L.; Kumar, P.; Huber, M. 2021
Self-aggregation of amyloid proteins is a crucial step in neurodegenerative disease. The protein alpha-synuclein (alpha S) is implicated in Parkinson's disease. In an extension of the demonstration... Show moreSelf-aggregation of amyloid proteins is a crucial step in neurodegenerative disease. The protein alpha-synuclein (alpha S) is implicated in Parkinson's disease. In an extension of the demonstration of in situ observation of intermediates in alpha S-aggregation by continuous wave (cw) EPR at room temperature (Zurlo et al. PLoS One 16: e0245548, 2021) by spin-label EPR, here the spin label is attached to position 90 (R1 alpha S90), rather than at position 56. The aim is to determine, if the spin-label position affects the kinetics of aggregation and if local information on the intermediates is accessible. Probed by the MTSL ((1-Oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate) spin label at position 90, using diamagnetic dilution of 9:1 wild type alpha S to R1 alpha S90, similar aggregation kinetics are found. Rotation correlation times for the spin label in the oligomer cannot be determined with sufficient accuracy to obtain local information on the oligomer under the conditions used. At the present stage, higher resolution EPR approaches, such as high-field EPR are more promising. Show less
