An efficient amperometric catechol sensor based on novel polypyrrole-carbon black doped α-Fe2O3 nanocomposite

Catechol reacts with a variety of biomolecules including DNA, proteins, membranes, etc. and thus causes irreparable damage to human health. Therefore, herein a highly sensitive and selective electrochemical catechol (CC) sensor based on a novel polypyrrole/carbon black doped α-Fe2O3 nanocomposite (PPy/CB/α-Fe2O3 NCs) modified glassy carbon electrode (GCE) is developed and demonstrated. The structural and morphological properties of the PPy/CB/α-Fe2O3 NCs were investigated by FESEM, TEM, EDS, XPS, XRD, FTIR, and Raman spectroscopy. This newly designed highly-sensitive PPy/CB/α-Fe2O3/GCE-based electrochemical sensor can measure a wide range of CC (0.5–1188 μM) in phosphate buffer solution (PBS) with a sensitivity of 0.3521 μAμM−1cm−2 and a logical limit of detection (LOD) 52.8 ± 0.1 nM. The selectivity of the proposed CC sensor was also examined in the presence of common interfering substances. Furthermore, the CC sensor electrode showed highly acceptable results towards the detection of CC level in real samples analysis by the standard addition method. This new combination of active materials, PPy/CB/α-Fe2O3 modified GCE exhibited excellent reproducibility, repeatability, and long-term stability during the electrochemical detection of catechol. Therefore, this approach will emerge as an effective technique in developing efficient electrochemical sensors to detect phenolic compounds for environmental safety. [Display omitted] •Polypyrrole (PPy)/carbon black (CB) doped α-Fe2O3 via sol-gel and sonothemical routes.•PPy/CB/α-Fe2O3 nanocomposite modified GCE as efficient amperometric catechol sensor.•Good sensitivity 0.3521 μAμM-1 cm-2, low LOD 52.8 ± 0.1 nM, wide range 0.5–1188 μM.•Excellent reproducibility, repeatability and storage stability of PPy/CB/α-Fe2O3/GCE.•Acceptable and validated analytical results of catechol in tap water samples.