I’m studying a hypothetical model for urease activity, which involves fluorescence measurement, hence the need for an optical window to which the enzyme urease is immobilised. From my previous knowledge, immobilisation of enzymes on a solid surface is done through the covalent bonding of the enzyme (outside its active site) with a functional group on the solid surface capable of covalent bonding. My question is, isn’t glass supposed to be inert? How can enzymes be covalently immobilised on glass? And if they can’t be, are there other materials that could be used instead of glass for an optical window?
Glass can be functionalized by organosilanization so that biomolecules can be covalently attached via some cross-linker. As an example, one might aminosilanize the glass and then cross-link their enzyme of interest with glutaraldehyde.
For what it’s worth, urease activity can be measured in solution.