Facile synthesis of lipase-loaded starch nanoparticles as recyclable biocatalyst in Pickering interfacial systems

To develop recyclable biocatalyst used in Pickering interfacial systems, the pH-responsive monomer [2-(dime-thylamine)ethyl methacrylate] (DMAEMA) was grafted onto the maize starch molecule via free radical poly-merization. Subsequently, combined with the gelatinization-ethanol precipitation and lipase (Candida rugosa) absorption process, an enzyme-loaded starch nanoparticle with DMAEMA grafting (D-SNP@CRL) was tailor-made, showing a nanometer size and regular sphere. X-ray photoelectron spectroscopy and confocal laser scanning microscopy confirmed a concentration-induced enzyme distribution within D-SNP@CRL, thereof the outside-to-inside enzyme distribution was proved to be optimum in achieving the highest catalytic efficiency. Benefited from the tunable wettability and size of D-SNP@CRL under pH variation, the generated Pickering emulsion could be readily applied as the recyclable microreactors for the n-butanol/vinyl acetate trans-esterification. This catalysis exhibited both highly catalytic activity and good recyclability, making the enzyme -loaded starch particle a promising green and sustainable biocatalyst in the Pickering interfacial system.

Automated summary

In this study, a pH-responsive monomer was grafted onto maize starch molecules to develop a recyclable biocatalyst for Pickering interfacial systems. The resulting enzyme-loaded starch nanoparticle showed nanometer size and regular sphere, and exhibited highly catalytic activity and good recyclability. The generated Pickering emulsion could be used as recyclable microreactors, making this biocatalyst a promising option for green and sustainable catalysis in Pickering interfacial systems.