Low dimensional Bi2Se3 NPs/reduced graphene oxide nanocomposite for simultaneous detection of L-Dopa and acetaminophen in presence of ascorbic acid in biological samples and pharmaceuticals

Graphene-based inorganic layered materials have developed as a versatile, new class of nanomaterials and drawn huge scientific interest, owing to its thickness-dependent physical properties, exfoliated two-dimensional crystals in various technological and industrial applications. This work is the first demonstration of the fabrication of low dimensional bismuth selenide (Bi 2 Se 3 ) NPs functionalized reduced graphene oxide (rGO) on the platinum electrode (Pt-E) for the ultra-sensitive and simultaneous detection of acetaminophen (ACT) and L-DOPA (LD) in the presence of ascorbic acid (AA) in various biological samples and pharmaceuticals. The constructed electrode accelerates the electron transfer reactions of LD and ACT without interfering with the electron transfer reactions of AA, which was an electroactive coexisting chemical. At pH 6.0 in 0.1 M phosphate buffer solution, Bi 2 Se 3 NPs/rGO/Pt-E showed a sixfold and fivefold increase in cyclic voltammetry for LD and ACT signals, respectively, when compared to bare Pt-E. Under the optimal conditions, differential pulse voltammetry (DPV) demonstrated that the anodic peak currents were linearly dependent on the concentrations of LD (0.006–0.25 mM) and ACT (0.0045–0.14 mM) at anodic peak potentials of + 0.25 and + 0.52 V, respectively. With a signal to noise (S/N) ratio of 3, acceptable detection limits of 0.23 and 0.17 M were achieved for both LD and ACT, with strong intra- and inter-electrode repeatability. Overall, the fabricated nanosensor offered numerous advantages including ease to fabricate, ultra-sensitivity, good stability, and reproducibility towards the detection of LD and ACT in various bioloical samples and pharmaceuticals. The amounts of LD and ACT were also identified in commercial pharmaceuticals and synthetic urine samples to validate the applicability of the modified electrode.