Electrochemical Sensing of Paracetamol Using Iron Oxide Encapsulated in Chitosan-Grafted-Polyaniline

Potentiometric sensing of paracetamol over molecularly engineered and chemically responsive α-Fe2O3 encapsulated chitosan grafted polyaniline (α-Fe2O3-en-CHIT-g-PANI) coated ITO glass electrode has been demonstrated. The effect of molecular engineering on the structure, morphology and physical properties of α-Fe2O3-en-CHIT-g-PANI was investigated by Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and two probe methods. The observed result suggests the formation of a porous hybrid matrix with improved electrical conductivity (∼6.25 × 10–4 S·cm–1), oriented crystallinity, better adsorption capacity and responsiveness due to optimized molecular structure and aligned crystallinity. Furthermore, a film of obtained hybrid on ITO-coated glass was explored for potentiometric sensing of paracetamol under optimum conditions (pH = 7.0 and 25 °C) with efficient sensing properties viz sensing range 5.0–100.0 μM, sensitivity 1.1 mV·μM–1·cm–2, response time 50 s, recovery time 20 s, limit of detection (LOD) 5.7 μM, and stability for 40 days. Then, sensing mechanism, charge transport, and switching behavior have been also explained on the basis of developed induced potential due to surface interaction between paracetamol and α-Fe2O3-en-CHIT-g-PANI matrix. Analytical performances of the developed electrode in a real sample have been also explored for the on-site detection of residual paracetamol in different pharmaceutical samples.