Bio-based microfluidics with snail slime: A by-product of agriculture plays an exciting role in the chemistry of microfluidic reaction chambers.

Snail slime, respectively mucus, presents great potential due to its broad spectrum of ingredients, including the eponymous structural proteins (Mucins), glycoproteins and bioactive compounds such as hyaluronic acid and allantoin. It is most prominently applied in the cosmetic industry as raw material for the production of protein-based hybrid hydrogels, and is also known to have potential for synthetic chemistry. For instance, it has been shown to have the ability to form catalytically active gold NPs (Au-NPs) under mild conditions. In our research we combine these key features, the ability to reduce gold solutions, stabilize their NPs and be a chemical building block, for developing Au-NP-comprising hydrogel structures from snail slime. Au-NPs are produced under environmentally friendly conditions and integrated into bio-based hydrogels for a sustainable reaction process. In the form of micro-scale dots, the newly designed Au-NP-hydrogels are successfully implemented in a microfluidic single-chamber reactor and utilized for the decolouration (=degradation) of Rhodamine 6G. We hence present a path towards a multi-functional environmentally friendly microfluidic test chip, utilizing the versatile catalytic activity of green gold NPs, embedded in biogenic, hydrogel materials.