Screen Printed Carbon Electrodes Modified with 3D Nanostructured Materials for Bioanalysis: A Comparison Study

Abstract

Here, the modification of screen printed carbon electrodes (SPEs) with 3D structured MWCNT-sponge (MWCNT-Spng) Au nanoparticle modified MWCNT (MWCNT-Spng-AuNPs) and graphene foam (GF) along with their impact on analytical performance was reported. The bare and modified SPE electrodes were imaged and characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). The results confirmed the successful modification and the improvement in charge transfer resistance (Rct). The modified electrodes were tested for electrochemical detection of dopamine (DA) and a significant improvement was observed in terms of both limit of detection (LOD) and sensitivity as compared to bare SPE. MWCNT-Spng-AuNPs/SPE demonstrated the highest analytical performance for DA with an LOD of 0.83 µM and a sensitivity of 183.121 µA/mM·cm2. It was also tested for enzyme-free glucose detection, in which case it demonstrated an LOD of 7.63 µM and a sensitivity of 408 µA/mM·cm2, along with a good selectivity for glucose. Overall, modification of SPEs with such 3D carbon-based nanomaterials can greatly improve their analytical performance, which is essential for the sensitive and selective detection of biologically relevant molecules.