The influence of preparation method on the efficiency of clay-carbon composites for detection of 4- aminoantipyrine

Smectite-rich bentonite clay was used to synthesize a chitosan-smectite nanocomposite. The resulting nanocomposite underwent two carbonation procedures: air-limitation pyrolysis and hydrothermal treatment. The obtained clay-carbon composites were characterized using XRD analysis, FT-IR, and Raman spectroscopy. The point of zero charge was determined for both composites. Electrochemical characterization was performed via cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical activity of carbon paste electrodes modified with the clay-carbon composites was evaluated for 4-aminoantipyrine (4-AAP) detection in Britton-Robinson buffer (pH 3–9) using cyclic voltammetry. The sensor based on the hydrothermally synthesized composite was further tested by square wave voltammetry, achieving a sensitivity of 0.0125 μA/μM and a detection limit (LOD) of 0.4 μM. The sensor demonstrated satisfactory performance when tested in real urine samples.