The nanostructured dysprosium oxide ( Dy2O3) was synthesized by the co-precipitation method and incorporated with graphitic carbon nitride (g-C3N4) using the ultrasonication method. The resultant product is denoted as Dy2O3/ g-C3N4 nanocomposite which was further used for electrochemical sensing of riboflavin (RF). The physicochemical properties of Dy2O3/ g-C3N4 nanocomposite were examined using several characterization techniques. The obtained results exhibit the nanocomposite formation with the preferred elemental compositions, functional groups, crystalline phase and desired surface morphology. The electrocatalytic performance of Dy2O3/ g-C3N4 nanocomposite was scrutinized with a glassy carbon electrode (GCE) via differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques with the conventional three-electrode system. The modified electrode distributes more active surface area suggesting high electrocatalytic activity for the RF detection with two linear ranges (0.001–40 μM and 40–150 μM), a low detection limit of 48 nM and sound sensitivity (2.5261 μA μM−1 cm− 2). Further, the designed sensor possesses high selectivity, excellent stability, repeatability and reproducibility. Finally, the fabricated sensor was successfully estimated for the detection of RF in actual food sample analysis using honey and milk with better recovery.

In this work, the effect of co-carbon fillers on the electrical and mechanical properties of epoxy nanocomposites was investigated. The graphite nanosheets (GNs) and multi-walled carbon nanotubes (MWNTs) were used as co-carbon fillers. The results showed that the electrical conductivity of the epoxy nanocomposites showed a considerable increase upon an addition of MWNTs when GNs were fixed at 2 wt.%. This indicated that low content GNs formed the bulk conductive network and then MWNTs added were intercalated between the GN layers, resulted in the formation of additional conductive pathway. Furthermore, the flexural strength of the epoxy nanocomposites was enhanced with increasing the MWNT content. It was probably attributed to the flexible MWNTs compared with rigid GNs, resulted in the enhancement of the mechanical properties.