Immobilization of lipase in Langmuir - Blogett film of cubic silsesquioxane on the surface of zirconium dioxide

In this work, we report on the formation of interfacial films by amphiphilic, incompletely condensed silsesquioxane and enzyme, lipase. Besides, we deposited the mixed film on the surface of zirconium dioxide to be used as an efficient biocatalyst. The films were characterized at the air/liquid interface using the surface pressure area isotherms, relaxation curves and dilatational rheology. For the characterization of the films deposited on a solid substrate we used atomic force microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and low temperature N-2 sorption analysis. The results are discussed in terms of formation, stability, and enzymatic activity of silsesquioxane lipase interfacial film depending on enzyme concentration, properties of zirconia, and storage time. Lipase immobilized into the ultrathin film of trisilanolcyclohexyl POSS (TCyPOSS) exhibited high activity and could be recycled three times while retaining relatively high activity (ca. 70% for TCyPOSS+LP/ZrO2 and 60% TCyPOSS+LP/ZrO2-NHx). The effect of storage time on the activity of immobilized lipase was studied as well. Lipase immobilized in Langmuir Blodgett film built by TCyPOSS on ZrO2 and ZrO2-NHx surface retained 98% activity after 7 days. We showed that the coating of zirconia by TCyPOSS film with the incorporated enzyme is a promising strategy for the immobilization of lipase with the controlled architecture at a molecular level.

Automated summary

This study reports on the formation of interfacial films by amphiphilic, incompletely condensed silsesquioxane and enzyme, lipase, and their deposition on zirconium dioxide surface for use as a biocatalyst. The results indicate that this method can achieve high enzymatic activity, with the immobilized lipase showing promising stability and reusability. The strategy of coating zirconia with TCyPOSS film incorporating enzymes shows potential for controlled architecture at a molecular level.