Modification of Quartz Crystal Microbalance Surfaces via Electrospun Nanofibers Intended for Biosensor Applications

Abstract

The major aim of this study is to increase the performance of mass sensitive biosensor surfaces by making modifications on quartz crystal microbalance (QCM) surfaces via electrospinning and plasma polymerization techniques. Polyvinyl alcohol (PVA) nanofibers with a diameter of approximately 150 nm were collected on the QCM surfaces by electrospinning technique. Allylamine monomer was used to create specific groups on these nanofiber coated surfaces by plasma polymerization technique. Modified surfaces were characterized by contact angle measurements, scanning electron microscopy, atomic force microscopy, fourier transform infrared spectroscopy and QCM frequency measurements in order to determine the physical and chemical characteristics of the surfaces after each experimental stage. N-H, C-N, C-H and C=O group bands were determined in the IR spectra of the materials. Decrease in the contact angle values of the modified materials indicated the increase in hydrophilicity. Those results showed that amine containing films on the surfaces were successfully deposited using plasma. The performance of modified QCM surfaces was tested via resonance frequency shifts measurements after bovine serum albumin immobilization. In this group of tests, "dip and dry" method and "flow-cell method" were performed and 548 +/- 4 Hz and 50 +/- 5 Hz frequency shifts were obtained respectively. Results of this study revealed that plasma treated electrospun PVA nanofiber modified surfaces can be used for further biosensor applications.