High generation dendrimer decorated poly-Ɛ-caprolactone/polyacrylic acid electrospun nanofibers for the design of a bioelectrochemical sensing surface

Abstract

In this study, poly-Ɛ-caprolactone (PCL) and poly(acrylic) acid (PAA)-based electrospun nanofibers were prepared for the immobilization of pyranose oxidase (PyOx) to design a bioelectrochemical detection system. Different amounts of PAA were used to increase hydrophilicity (decreased contact angle) of the PCL electrospun nanofibers. To provide a multipoint attachment side to bind PyOx by covalent bonds, various amounts of high generation (G5) poly(amidoamine) (PAMAM) dendrimer with amino groups were added to the PCL:PAA backbone. To attach PyOx onto the PCL:PAA/PAMAM electrospun nanofibers, glutaraldehyde was used as a homobifunctional crosslinker. Firstly, PCL:PAA ratio was optimized to obtain the best electrospun nanofibers without beads and with decreased contact angle. Then, the effect of the PAMAM amount on the morphology of PCL:PAA and contact angle was tested. The obtained PCL:PAA/PAMAM electrospun nanofiber was characterized by scanning electron microscopy (SEM). Then, the presence of PAMAM in the structure and the success of PyOx immobilization onto PCL:PAA/PAMAM were proven by SEM and an energy dispersive X-ray analyzer (SEM-EDX). Finally, PCL:PAA/PAMAM/PyOx was characterized, calibrated, and applied to analyze glucose in samples without any interfering effect of some chemicals. Briefly, the nanofibers modification with dendrimers and the conjugation of PyOx onto formed nanostructures was successfully performed, and a novel electrospun nanofiber-based sensor system was developed for target detection.