Electrochemical Sensing of Acetaminophen Using Strontium Chlorapatite: Experimental and Computational Insights

ABSTRACT Strontium hydroxyapatite (SrHA) and its halogen‐substituted derivatives, strontium fluorapatite (SrFA) and strontium chlorapatite (SrClA), were synthesized using a chemical precipitation method and characterized using XRD, FT‐IR, and FE‐SEM. The incorporation of fluorine and chlorine into the SrHA lattice affected the crystal structure and morphology of the material. Electrochemical investigations revealed that SrClA exhibited the largest electrochemical surface area among the synthesized materials, which directly correlated with its enhanced acetaminophen (AC) sensing capability. The key parameters, including pH, accumulation time, and scan rate, were optimized to maximize the sensor response. Under optimized conditions, the SrClA‐modified carbon paste electrode achieved a low limit of detection of 79 nM for AC, with a wide linear concentration range (5–200 µM). Density Functional Theory (DFT) studies provided insights into the sensing mechanism, revealing the strongest interaction between AC and SrClA, corroborating the electrochemical findings. The hydroxyl and carbonyl oxygens of AC showed favorable adsorption, with binding energies indicating the order of interaction strength as SrClA > SrHA > SrFA. These results highlight the potential of SrClA as a sensitive and effective electrochemical sensor for AC detection, offering a promising approach for rapid and accurate analysis.