Protein–polyelectrolyte complexes to improve the biological activity of proteins in layer-by-layer assemblies†
A standard method of protein immobilization is proposed, based on the use of protein–polyelectrolyte complexes (PPCs) as building blocks for layer-by-layer assembly. Thicker multilayers, with a higher polyelectrolyte fraction, are obtained with PPCs compared to single protein molecules. Biological activity is not only maintained, but specific activity is also higher, as demonstrated for lysozyme–poly(styrene sulfonate) complexes. This is attributed to the more hydrated state of the assemblies. This new method of protein immobilization opens up perspectives for biotechnology and biomedical applications.