Azo dye functionalized graphene nanoplatelets for selective detection of bisphenol A and hydrogen peroxide

Abstract

Graphene nanoplatelets (GNP) have emerged as a promising electrode material for electrochemical sensing applications because of their high conductivity, large surface-to-volume ratio, biocompatibility, and low cost. However, GNP are not soluble in water. We dispersed GNP in water with the assistance of a tri-azo dye, Direct blue 71 (DB). Thin films prepared with GNP/DB dispersion were characterized by scanning electron microscopy (SEM), Raman spectroscopy, and UV-vis spectroscopy, which indicated the binding of DB with GNP films. The GNP/DB film coated glassy carbon electrode (GCE) exhibited high electrocatalytic activity to oxidation of bisphenol A (BPA) and reduction of hydrogen peroxide (H 2 O 2 ). The GNP/DB film greatly enhanced the BPA oxidation peak current at +524 mV, and the H 2 O 2 reduction peak current at -400 mV vs. Ag/AgCl in pH 7.0 phosphate-buffered saline (PBS) solution. The oxidation peak current was proportional to BPA concentration from 10 nM to 100 nM and 100 nM to 25 µM, with a limit of detection of 1.23 nM. The GNP/DB-modified GCE also showed remarkable decrease of over-potential for the reduction of H 2 O 2 with a fast amperometric response of less than 2 s, good linear range of 10 µM to 1.9 mM, and high sensitivity of 57.6 µA/mM. The fabricated sensor shows good reproducibility and stability with limited interference. Furthermore, the sensor was successfully applied to determine BPA in spiked commercial milk and juice samples.A new electrochemical sensor is developed based on graphene nanoplatelets functionalized with tri-azo dye (Direct blue 71) for selective and highly sensitive detection of bisphenol A and hydrogen peroxide in pH 7 phosphate buffered saline solution.

Gold Nanoparticles-Thiol-Functionalized Reduced Graphene Oxide Coated Electrochemical Sensor System for Selective Detection of Mercury Ion

“…Subsequently, the electrode was tested by recording cyclic voltammograms (CVs) in 5 mM K 4 [Fe(CN) 6 ] and K 3 [Fe(CN) 6 ) in 0.1 M KCl solution. [32][33][34] Step 2). Later, the GCE/rGO-SH/Au-NPs was gently washed using distilled water to remove any loosely bounded materials from the electrode surface.…”

Rapid and on-site electrochemical detection of bisphenol A and arsenic indrinking water using a novel electrode array

“…The electrochemical oxidation mechanism of bisphenol A at the electrode surface. 22 As the diameter of the electrodes decreases, the current density increases; however, this also means that the magnitude of the sensor responses decreases. While very small electrodes may result in high current density, at very low analyte concentrations the sensor may result in no response at all.…”

Direct and Sensitive Electrochemical Detection of Bisphenol A in Complex Environmental Samples Using a Simple and Convenient Nanochannel-Modified Electrode

“…(Liu et al, 2020;Sabbaghan et al, 2021;Xuan et al, 2021;Ghalkhani and Sohouli, 2022) The electroactive phenolic hydroxyl groups in BPA enable its detection by electrochemical sensing. To improve the detection sensitivity, researchers have used a variety of materials to modify the working electrode, including metal or metal oxide nanoparticles (Ashraf et al, 2020;Wang et al, 2020b;Yang et al, 2022), carbon materials (Yasri et al, 2015;Alam and Deen, 2020;Zhu et al, 2020;Ponnada et al, 2022;Wang et al, 2022), ionic liquids (Wang et al, 2018;Wang et al, 2021b), molecularly imprinted polymers (Beduk et al, 2020;Zhang et al, 2021), metals and covalent organic frameworks (Zhang et al, 2018;Pang et al, 2020), and aptamers (Hadi et al, 2016;Jun et al, 2020). However, these modified electrodes often require expensive reagents/ materials or complicated synthesis processes.…”