효소 고정화를 위한 PDMS 기반 폴리아닐린 나노섬유 제조 및 응용

Abstract

Nanofibers with high surface area to volume ratio were prepared using polyaniline (PANI) and the surface of electrospinned poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) was coated with them for enzyme immobilization. In order to overcome the low solubility of PANI, 2-acrylamido-2-methyl-1-propansulfonic acid (AMPSA) and 4-dodecylbenzenesulfonic acid (DBSA) with long alkyl chains were used to resolve PANI. Since the viscosity increased rapidly with the addition of PANI, the PANI concentration was limited to a maximum of 20 wt% for electrospinning. In order to control the size and handle the fiber carrier easily, nanofibers were electrospun on the surface of micropatterned polydimethylsiloxane (PDMS) and used as an enzyme reactor for immobilization. PVdF-HFP/PANI was incoporated into a microfluidic device consisting of a reaction chamber with inlet and outlet flows. It has been found that polyaniline can be used as an additive to improve the enzymatic activity and stability of nanofibers. The presence of amine groups in PVdF-HFP/PANI nanofibers confirmed improved enzyme activity and stability, pH, thermal stability, good reuse and long-term storage. The immobilized lipase and β-galactosidase showed excellent reusability even after 10 cycles of reaction and the residual activities of them were over 90% and 60%, respectively. The PVdF-HFP/PANI/Lipase showed enhanced enzyme catalytic performance at a residence time of 7.8 s using microreactor. 27.1% of p-nitrophenol conversion and 12.3 mol/h·L of productivity were achieved with 0.1 mM of p-NPB. PVdF-HFP/PANI/Lipase retain over 75.2% of their initial activity after 65 days. The PVdF-HFP/PANI/β-galactosidase microreactor showed enhanced catalytic performance at a residence time of 10.4 s. 27.4% of o-nitrophenol conversion and 9.4 mol/h·L of productivity of were achieved with 0.1 mM of ONPG. The enzyme reaction rates using developed microreactor increased 1081.3 times for lipase and 248.7 times for β-galactosidase more than those with batch reactor.