초록
<P>Cationic polyelectrolyte doped hollow nanofibers prepared via facial coaxial electrospinning technology have been used for positional assembly of two enzymes, glucose oxidase (GOD) and <I>Candida antactica</I> lipase B (CALB), at two different positions, namely, in their lumen and on their surface. Therefore, the result is four combinations, including lumen (GOD+CALB), surface (GOD+CALB), surface (GOD)-lumen (CALB), and lumen (GOD)-surface (CALB). Surface attachment of enzymes was achieved by layer-by-layer (LbL) technology, which is based on the ion-exchange interactions between oppositely charged enzymes and polyelectrolyte that was doped in hollow nanofibers; whereas placing enzymes inside the lumen of hollow nanofibers was realized by in situ encapsulation during coelectrospinning. The hollow nanofibers-based bienzyme systems were used for a cascade reaction in an oil-aqueous biphasic system, in which glucose was oxidized by GOD to generate H<SUB>2</SUB>O<SUB>2</SUB>, which was used as substrate and oxidant for CALB-catalyzed epoxidation of oleic acid in the second step. The bienzyme nanofibers membrane was found to float spontaneously at the O/W interface, which is advantageous to biphasic biocatalysis. Assembly strategies of the two enzymes affect their biocatalytic efficiency significantly by influencing the utilization efficiency of H<SUB>2</SUB>O<SUB>2</SUB> in the reaction process. The highest reaction rate was attained by lumen (GOD)-surface (CALB), corresponding to 114.45 times enhancement as compared to that of the free bienzyme system.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/accacs/2014/accacs.2014.4.issue-12/cs501383j/production/images/medium/cs-2014-01383j_0014.gif'></P>