Polyethylene Glycol–Enzyme Nanocomplexes as Carrier-free Biocatalyst for Pickering Interfacial Catalysis

PEG-enzyme nanocomplexes are prepared and stabilized in an oil-in-water-type emulsion for Pickering interfacial biocatalysis, and these nanocomplexes function as catalysts and emulsifiers at the emulsion interface. The nanocomplexes are self-assembled by cross-linking mPEG-ALD with lipase, without complicated synthesis steps, toxic chemical reagents, and external carriers. Moreover, the mild cross-linking process preserves the original structure of the enzyme, the retention rate of enzyme activity is 82.1%, and the nanocomplexes are used to emulsify biphasic aqueous-organic solution into Pickering emulsion. The system exhibits excellent reusability, with enzyme activity remaining at 86.05% after five cycles, providing a desirable eco-friendly platform for carrier-free Pickering interfacial biocatalysis.