Two synthetic strategies were developed for in-situ modification of a silica sol gel matrix in a PEEK tubing, to obtain a hybrid monolith with entrapped lipases. A suitable combination of the sol-gel precursors (tetramethoxysilane, methyltrimethoxysilane and n-propyltrimethoxysilane) was found, for the simultaneous improvement of the monolith adhesion to the tubing internal surfaces and of the catalytic properties of the entrapped enzyme. The effects of the immobilization procedure were characterized as regards both the catalytic properties of the enzyme, as well as the secondary structure of lipases by FTIR. The catalytic efficiency of the entrapped enzyme was better preserved in more hydrophobic microenvironment. The improved stability of...