(322f) Dispersion of Polystyrene - Poly (Styrene-Co-Maleic Anhydride) Nanofibers in Aqueous Solutions for Biocatalytic Continuous Flow Reactors

Electrospun nanofibers of hydrophobic polymers are ideal supports for the immobilization of enzymes. However, they are not well dispersed in aqueous solutions and prefer to exist as a tightly aggregated non-woven mat, leading to a reduction in the area available for the enzyme immobilization. This can also pose mass transport problems during the enzyme loading on the nanofiber surface inside the non-woven mat and the reactions of the immobilized enzymes with the substrates dissolved in aqueous solution. In order to maximize the enzyme coverage and the enzymatic activity on the nanofiber surface , it is desirable to disperse these immobilization supports in the reaction media. Conventional surfactants can disperse the electrospun non-woven mat in aqueous solutions but this is not preferred since these surfactants can denature the enzymes. In this work, we present a simple and efficient method for dispersing electrospun nanofibers of polystyrene (PS)- poly(styrene-co-maleic anhydride)(PSMA) in water without using conventional surfactants. This method involves treatment of the electrospun non-woven mat with an aqueous alcohol solution before immobilizing enzymes. The effect of the alcohol treatment of PS-PSMA fibers on the enzyme coverage and enzyme activity was studied by the immobilization of lipase onto the nanofibers. Both the enzyme coverage and the enzyme activity increased with the dispersion of the PS-PSMA nanofibers, as compared to the as-spun PS-PSMA nanofibers. The alcohol dispersed PS-PSMA nanofibers will be immobilized with glucose oxidase for application as a continuous flow reactor. The activity and stability of the glucose oxidase on the alcohol dispersed PS-PSMA nanofiber supports will be studied. The improved enzyme loading and activity onto these well dispersed supports will help design efficient biocatalytic systems for bioremediation and biosensing.