Fabrication of nonenzymatic electrochemical interface for ratiometric and simultaneous detection of hydrogen peroxide, dopamine, and ascorbic acid

Abstract

In this work, a novel electrochemical platform of boronic acid pinacol ester compound modified carbon nanotubes (CNTs) coupled methylene blue (MB) was developed for ultrasensitive and simultaneous determination of hydrogen peroxide (H2O2), dopamine (DA), and ascorbic acid (AA). MB and CNTs were used as internal reference and signal amplification medium, respectively, for accurate and rapid detection of H2O2, DA and AA in complex environments. A turn-on electrochemical probe of 4-(pyren-4-yl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl) butanamide (BP) modified on CNTs via π-π stacking was designed for the nonenzymatic detection of H2O2 based on the oxidation of phenol groups. When simultaneous detection of H2O2, DA, and AA, the oxidation peak potentials of the three compounds on the electrode could be well separated and the electrochemical platform showed excellent linear range and ultrasensitive response to the three components, and the detection limits for H2O2, DA, and AA were estimated to be as low as 0.62, 0.15, and 3.8 μM, respectively (S/N = 3). The fabricated sensor also exhibited excellent stability and reproducibility. More importantly, we had successfully utilized this strategy for the detection of three analytes in real samples and satisfactory results were obtained.