The environmental persistence of organophosphate pesticides necessitates the development of multifunctional materials capable of simultaneous remediation and monitoring. This study introduces a bifunctional polyaniline-chitosan (PANI-Ch) nanocomposite, synthesized via in-situ oxidative polymerization, designed for the high-capacity adsorption and quantitative optical detection of the pesticide Sumithion. The PANI-Ch platform exhibited an exceptional adsorption capacity of 124.7 mg/g, following a Langmuir-type monolayer process. Thermodynamic and spectroscopic analyses revealed a physisorption mechanism dominated by π–π stacking and hydrogen bonding, supported by a mean free energy (E) of 0.027 kJ/mol. Beyond remediation, the nanocomposite functions as a robust sensing tool; Sumithion adsorption induces precise, concentration-dependent FTIR spectral shifts in the O–H/N–H and C = C stretching regions. These optical changes allow for trace-level quantification with a Limit of Detection (LOD) of 0.5 ppb. By integrating high efficiency scavenging with built-in analytical signaling, this nanocomposite provides a versatile and advanced platform for integrated water treatment and real-time environmental monitoring.
Sakr et al. (Sat,) studied this question.