Ultrasensitive detection of hydrogen peroxide and dopamine using copolymer-grafted metal-organic framework based electrochemical sensor.

We reported the synthesis of a copolymer- and metal-organic framework-based electrochemical sensor, UiO-66-NH2@P(ANI-co-ANA) using the polymerization method for the highly sensitive and selective detection of hydrogen peroxide (H2O2) and dopamine (DA). The as-synthesized material was characterized via Fourier transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The electrochemical characteristics of the proposed sensor were evaluated via impedance spectroscopy and cyclic voltammetry (CV). The electrochemical oxidation of DA and the reduction of H2O2 were determined via CV, square-wave voltammetry, and chronoamperometric techniques. The fabricated sensor exhibited a wide linear range of 25-500 μM, with a sensitivity of 1396.1 μAμM-1cm-2 and a limit of detection of 0.6 μM, for the electrochemical reduction of H2O2. Additionally, it exhibited a wide linear range of 10-110 μM, with a sensitivity of 1110.2 μAμM-1cm-2 and a limit of detection of 0.3 μM, for the electrochemical detection of DA. The practical utility of the fabricated sensor was evaluated via the detection of H2O2 in milk samples and DA in human urine samples.