Electrochemical simultaneous sensing of melatonin and ascorbic acid at a novel flexible B-RGO composite paper electrode

The present work demonstrates the fabrication and sensing performance of a free-standing paper electrode composed of boron oxide (B2O3) and graphene for the application of the simultaneous detection of melatonin (MEL) and ascorbic acid (AA). The flexible paper electrode (B-RGO) was fabricated through vacuum filtration of homogeneous composite dispersion (B-GO) consisting of B2O3 in GO, followed by chemical reduction with HI. The structural, chemical and morphological characterization of B-RGO composite paper was performed by using various techniques. This flexible paper electrode exhibited high sensitivity, wide linear range and low detection limit for the simultaneous determination of MEL and AA. The outstanding performance of B-RGO paper electrode could be attributed to the round-edged rod-like B2O3 structures between graphene layers, which provide an increment of the surface area and the electrochemical activity of the composite paper. Furthermore, this paper electrode showed high sensitivity and selectivity for the determination of MEL and AA in real sample analysis. [Display omitted] •A flexible graphene-based paper was fabricated through a simple vacuum filtration method.•The characterization of B-RGO composite paper was performed by using various techniques.•The B-RGO paper electrode showed good electrocatalytic activity for the simultaneous detection of MEL and AA.•This flexible paper electrode exhibited high sensitivity, wide linear range, and low detection limit.