Reusable and green approach to extract proteins with magnetic nanoparticles coated with carbosilane dendrimers: application to the recovery of whey proteins

The valorisation of industrial waste, such as whey from the dairy industry, offers a sustainable approach to reduce environmental impact while obtaining high value-added products. However, current protein extraction methods are often costly, prompting interest in innovative alternatives such as dendrimers and magnetic nanoparticles (MNPs), due to their functional versatility and reusability. In this work, a library of dendronized MNPs was proposed for protein extraction from whey. MNPs functionalized with different peripheral groups (amine, hydroxyl, carboxylate, and sulfate) were synthesized and tested for their ability to extract standard proteins under different dendrimer:protein ratios and pH conditions. The best performance was achieved with amine-functionalized MNPs, which could be reused up to 10 times after regeneration with a SDS solution. This system was also tested with a real cheese whey sample from the dairy industry, demonstrating promising results due to its recyclability and selectivity.