Enzyme-Immolbilized Microtubing

cross-linked enzyme aggregation - enzyme microreactor - immobilization - surface modification

Significance

<P>An enzyme-membrane was deposited on the inner surface of a microtubing via cross-linking of poly(Lys) matrix with glutaraldehyde and paraformaldehyde (crosslinker) under laminar-flow conditions. Concentric laminar flow was generated in a PTFE tubing (500 micrometer i.d.) by the introduction of the outer and center streams through the T-shape inlet and the silica capillary, respectively. When the phosphate buffer solutions of acylase-poly(Lys) aggregate and the crosslinker aldehyde were used as the outer and center streams, the crosslinking took place at the interface of laminar flow to form the enzyme membrane on the inner surface of the PTFE microtubing. The resulting enzyme-immobilized micro­-tubing was used as a flow reactor exhibiting the acylase activity.</P>

Comment

<P>The formation of an insoluble crosslinked polymer was achieved in a ship-in-a-bottle manner at the interface of laminar flow streams. Use of a multi-stream laminar flow for the localized formation of an insoluble salt inside a half-pipe-shaped microchannel has been originally reported by Whitesides and co-workers (Science 1999, 285, 83-85) and recently applied for the formation of a polymer membrane (e.g. 6,6-nylon) by Kitamori and co-workers (Anal. Chem. 2003, 75, 350-354).</P>