Photocatalytic and electrochemical sensor for direct detection of paracetamol comprising γ-aluminium oxide nanoparticles synthesized via sonochemical route

Abstract

Aluminium oxide nano particles (Al2O3 NPs) were synthesized using simple but effective probe sonication method. The structural, photocatalytic, and electrochemical sensor properties of Al2O3 NPs were investigated by powder X-ray Powder Diffraction (PXRD), Scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), UV–vis Spectroscopy, and Electrochemical analyzer potentiostat. The impact of sonication on the physical properties of Al2O3 NPs was elucidated. From the powder X-ray diffraction (PXRD) studies the material exhibited a face centered cubic structure and γ phase with crystallite size in the range from 6 to 16 nm. The semiconductor behavior has been confirmed from the study of energy band gap via diffuse reflectance spectroscopy (DRS). The conductivity of the samples was studied by cyclic voltammetry (CV) and Electrochemical Impedance spectroscopy (EIS) in 0.1 M HCl and 0.1 M NaOH as aqueous electrolytes. The electrode exhibited specific capacitance of 0.866 F g-1 and 0.488 F g-1 at scan rate 10 mV/s in acidic and alkaline electrolytes, respectively. EIS measurements showed reduction in the charge transfer resistance in acidic electrolyte. Modified carbon paste electrode employing γ-Al2O3 NPs has sensed Paracetamol in both acidic and alkaline electrolytes. The electrode displayed high sensitivity for paracetamol detection under varying concentrations. A linear calibration curve for paracetamol detection was obtained with a limit of detection (LOD) 2.3602 × 10−3 mol/L. These results confirm that the γ-Al2O3 NPs are promising electrode material for sensing paracetamol with high electrode reversibility and as an excellent photocatalyst.