Cerium oxide nanofiber based electroanalytical sensor for TNF-α detection: Improved interfacial stability with Nafion.

The present work is aimed at improving the adhesion of nanomaterials at the interface of solid state working electrodes. Towards this, herein, an efficient method has been proposed that requires the electrode interface to be decorated with an optimally thin layer of Nafion. This selectively permeable layer ensures the stability of the sensor interface, without hampering the transport of biomolecules and electrons. As a case study, here, electrospun Cerium oxide nanofiber (CeNF) modified Glassy carbon electrodes (GCE) have been used as the sensing interface, and stability and performance of the GCE/CeNF/Nafion interface is evaluated using analytical electrochemistry. The CeNF is synthesized via electrospinning and is characterized using X-ray diffraction spectroscopy, Thermal gravimetry, Fourier transform infrared spectroscopy, and Field emission scanning electron microscopy. Further, detection of sepsis specific biomarker TNF-α from spiked buffer samples is demonstrated, as a case study, towards evaluating the effect of Nafion on the interfacial sensitivity. The achieved LOD of GCE/CeNF and GCE/CeNF/Nafion for TNF-α detection were 2.8 fg/mL and 1.2 fg/mL, respectively. A comparative analysis between the Electrochemical impedance spectroscopic (EIS) results of the GCE/CeNF and the GCE/CeNF/Nafion interfaces confirms the improvement in stability, without affecting the sensitivity and the limiting detection.