Morphology and Entrapped Enzyme Performance in Inkjet-Printed Sol–Gel Coatings on Paper

We recently reported on the multilayer printing of sol–gel/enzyme bioinks onto porous filter paper to create bioactive paper test strips. The method involves printing of four inks: a polymer underlayer, a sol–gel-based silica layer, an acetylcholinesterase (AChE) enzyme layer, and finally a top layer of silica. To improve our understanding of the nature of these printed materials, filter paper printed with various ink components was …