Graphene nanoribbons and iron oxide nanoparticles composite as a potential candidate in DNA sensing applications

We report the synthesis and characterization of graphene nanoribbons (GNRs) decorated with iron oxide (Fe3O4) nanoparticles to obtain the GNR_Fe3O4 nanocomposite and its use as a DNA sensor. Characterization results confirm the successful synthesis of a nanocomposite based on reduced GNRs and mostly Fe3O4 nanoparticles distributed randomly and homogeneously on the ribbon's surface and whose specific surface area (766 m2 g−1) is higher compared to pure GNRs (588 m2 g−1). These characteristics make this nanocomposite suitable for effective DNA immobilization and hybridization in sensor applications. Taking advantage of the latter, the electrochemical analysis demonstrated that GNR_Fe3O4-based electrodes amplify the electrochemical signal by more than one order of magnitude compared to bare carbon electrodes, and 70% more compared to pristine GNRs-based electrodes. The capability of the GNR_Fe3O4 nanocomposite as a DNA sensor was evaluated in terms of the electrochemical response by monitoring the cathodic peak in DNA immobilization and hybridization through a redox process. The electrochemical current was measured in immobilized single-stranded DNA and double-stranded DNA to be 92 and 49 μA, respectively, for GNR_Fe3O4-based electrodes; these values are indicative of an effective discrimination between the immobilization and hybridization of DNA. The present work demonstrates the viability of a DNA sensor based on the facile synthesis of GNRs decorated with Fe3O4 nanoparticles.We report the synthesis and characterization of graphene nanoribbons (GNRs) decorated with iron oxide (Fe3O4) nanoparticles to obtain the GNR_Fe3O4 nanocomposite and its use as a DNA sensor. Characterization results confirm the successful synthesis of a nanocomposite based on reduced GNRs and mostly Fe3O4 nanoparticles distributed randomly and homogeneously on the ribbon's surface and whose specific surface area (766 m2 g−1) is higher compared to pure GNRs (588 m2 g−1). These characteristics make this nanocomposite suitable for effective DNA immobilization and hybridization in sensor applications. Taking advantage of the latter, the electrochemical analysis demonstrated that GNR_Fe3O4-based electrodes amplify the electrochemical signal by more than one order of magnitude compared to bare carbon electrodes, and 70% more compared to pristine GNRs-based electrodes. The capability of the GNR_Fe3O4 nanocomposite as a DNA sensor was evaluated in terms of the electrochemical response by monitoring the cathodic p...