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International audienceA general method is described for the covalent attachment to carbon surfaces of sensitive biomolecules such as antibodies. First, N-hydroxysuccinimide-activated carbon surfaces are prepared by a step by step method involving an electrografting process and a monoprotected homobifunctional linker to ensure a good control of the surface modification. Then, antibodies are introduced, at the last step of the modification procedure, under native conditions at physiological pH, to minimize their denaturation. Comparison with a classical method involving a homobifunctional linker shows a decrease of the degree of coverage of the surface by antibodies, explained by the formation of bridged structures by the linker

Hen egg yolk is largely used as an ingredient in food emulsions due to its exceptional emulsifying properties. Low-density lipoproteins (LDL) are the main egg yolk constituents and the most important contributors to yolk emulsifying properties. To better understand the LDL adsorption mechanism and spreading at the interface, we extracted and studied LDL at different interfaces. At the air-water interface, the LDL film isotherm presents three transitions, and two were identified by each lipid class present in LDL. The last transition should be due to apoproteins-lipids complexes. During LDL adsorption, the presence of apoproteins at the LDL surface and the neutral lipid core is necessary. At pH 3 and pH 7, LDL are disrupted and spread quasi-similarly at the air-water interface, contrary to the oil-water interface where LDL spread more at pH 7 than at pH 3.