Production of nafion/cellulose acetate hybrid nanofibers and investigation of their use in electrochemical biosensors

In this study, Nafion/cellulose monoacetate (CMA/N) hybrid nanofibers were produced via one step electrospinning method. As-spun nanofibers were collected on plain aluminum foil for material characterizations and on the cylindrical graphite electrode for electrochemical guanine oxidation signal analysis of neat and NH-modified single strand DNA (ssDNA). Various ratio of CMA/N were examined to obtain uniform hybrid nanofibers with maximum nafion ratio. Increasing nafion ratio led inhomogeneous solution property and solution transformed from transparent to blurry phase. At the same time, nanofibers morphologies transformed from uniform structure to bead on a string defect morphology with increasing nafion ratio in CMA/N hybrid nanofibers. Melting point of CMA is detectable at DSC measurement, but addition of nafion did not allow a proper crystallization of CMA and melting peak disappeared after nafion addition. Thermal degradation temperature decreased dramatically with addition of nafion into CMA/N hybrid nanofibers and decomposition took place at a broad temperature range. Differential pulse voltammetry (DPV) analysis were conducted to observe guanine oxidation signal at neat and NH-modified DNA by using as-prepared sensory system. Maximum oxidation signals were obtained from pure CMA nanofibers at neat ssDNA. Comparing neat DNA, signal intensity increased with addition of nafion into CMA/N nanofibers at NH-modified ssDNA sample since it may be an interaction between NH groups on ssDNA and SO3 groups on nafion as well as hydrogen bonding between ssDNA and OH groups on CMA. Strong interaction between biosensor surface and ssDNA molecule could be the reason for signal enhancement. The examined CMA/N hybrid nanofibers can be a promising interface for DNA biosensor devices.