One-Step Fabrication of Electrospun Photo-Cross-Linkable Polymer Nanofibers Incorporating Multiwall Carbon Nanotubes and Enzyme for Biosensing

Abstract

Herein, we report the easy and rapid fabrication of water-stable electrospun nanofibers from blends of the photochemically crosslinkable polyvinyl alcohol styrylpyridinium polymer (PVA-SbQ), carboxylated multiwall carbon nanotubes (MWCNT-COOHs) and glucose oxidase (GOx) for electrochemical biosensor application. Different electrospinning parameters including flow rate, applied voltage, distance between tip and collector, polymer concentration and MWCNT-COOHs content in the electrospun solution were tailored to produce PVA-SbQ/MWCNT-COOH nanofibers with minimal beading and enhanced electrical properties. Optimal PVASbQ and MWCNT-COOHs concentrations were 6.7 wt% and 5 wt% with respect to the total solution and polymer mass, respectively. The nanofibers were rendered water insoluble via exposure to UV irradiation for 10 min. The electrochemical properties of electrospun PVA-SbQ/MWCNT-COOH nanofibrous mats were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofibers. GOx, used as model enzyme, was further incorporated into the PVA-SbQ/MWCNT-COOH mixture before electrospinning. The obtained biosensor enabled successful detection of glucose by cyclic voltammetry. The resulting novel glucose biosensor revealed very good storage and operational stabilities, a low limit of detection (2 μM Electrospinning is a very convenient method to produce polymer nanofibers (NFs) and nanofibrous non-woven mats exhibiting high surface-to-volume ratio.1-3 Over the last decade, this method has gained a huge interest because of its simplicity, versatility, and relatively low cost. The typical setup consists of three parts: a) a syringe needle (associated to a syringe and a syringe pump) with a droplet of polymer solution hanging at the tip, b) a ground electrode used as the fiber collector, and c) a high voltage source which creates an electrical potential difference between syringe needle and collector (Fig. 1). When the electrical field strength exceeds a critical value, electrical repulsion between charges of the same polarity, accumulating at the droplet surface, will exceed the surface tension and an electrically charged polymer jet is extracted. The fluid jet is accelerated and stretched by the external electric field and becomes dramatically thin while travelling toward the collector, leading to the formation of a continuous solid fiber as the solvent evaporates. Fiber diameter, morphology and arrangement in space can be controlled by a proper selection of the spinning parameters and of the solution composition. Using this approach, NFs have been produced for a variety of applications, such as tissue engineering, 4 energy storage, [5][6] electronics, 7-8 gas sensors. 9-10 Applications of NFs to the elaboration of electrochemical sensors and biosensors is very promising but is still at an early stage. [11][12] Biosensors are very innovative and performing analytical devices that have ...

Enhanced performance of immobilized laccase in electrospun fibrous membranes by carbon nanotubes modification and its application for bisphenol A removal from water

“…1). This was mainly due to the fact that the addition of MWCNTs could enhance the conductivity of the spinning solution, resulting in a decrease of the fiber diameter [26,27]. If continuing to increase the MWCNTs dosage to 2.0 wt%, the fibrous diameter became fine, but some beads also appeared in the fibers (Fig.…”

“…Various MWCNTs modified EFMs (MWCNTs-EFMs) have been prepared for the immobilization of enzyme, and many studies have demonstrated that MWCNTs could effectively increase electron transfer between enzymes and membrane electrodes or substrates [23][24][25]. However, most of researchers prepared the MWCNTs-EFMs firstly, and then immobilized enzymes on the surface of membrane by adsorption or crosslinking attachment [23,25,26]; some obtained the MWCNTs modified enzyme-carrying EFMs through co-electrospinning the mixture of the MWCNTs/enzyme/polymer solutions [27]. There are few reports on the preparation of enzyme-carrying EFMs by emulsion electrospinning for improving their performances.…”

Recent Advances in Electrospun Nanofiber Interfaces for Biosensing Devices

“…This approach has been extensively used to immobilize enzymes [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], antibodies [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], DNA strands [ 71 , 72 , 73 ] and aptamers [ 74 , 75 ]. Another way to proceed, more specifically developed for enzyme biosensors, consists in entrapping the bioactive molecules inside the NFs by electrospinning a blend of enzymes and polymer [ 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 ].…”

Cyclodextrin-Based Nanofibers and Membranes: Fabrication, Properties and Applications

“…Figure 5 shows a setup of an electrospinning instrument with a flat stationary collector. The setup consists of a high-voltage supply, polymer solution in a syringe and the collector screen [42].…”

“…Schematic illustration of electrospinning setup with flat stationery collector. Reproduced with permission from[42].…”