Molecular‐Level Design of Polymer‐Based Multiwalled Carbon Nanotube Sensors for Chloramphenicol Detection Using DFT

ABSTRACT Chloramphenicol (CLM) is a potent broad‐spectrum antimicrobial agent used to treat infections caused by Gram‐positive and Gram‐negative bacteria, spirochetes, chlamydia, and rickettsia. Despite its medical significance, unregulated exposure through the food chain poses severe health risks. This emphasizes the urgent need for sensitive detection strategies in pharmaceutical, environmental, and food safety applications. In this study, we employ density functional theory (DFT) simulations to explore the interaction of CLM with a polypyrrole (Ppy)/multiwalled carbon nanotube (MWCNT) nanocomposite theoretically whose experimental studies have already been published. Using DMol 3 calculations in the Materials Studio framework, we analyze electronic interactions, charge‐transfer mechanisms, and binding affinities to optimize sensor performance. Our findings demonstrate that integrating Ppy with MWCNT significantly enhances sensitivity by increasing surface area and improving electronic conductivity. Binding energy calculations confirm a strong affinity between CLM and the nanocomposite, surpassing that of individual components and supporting published experimental results, where the voltammetry‐based detection tests reveal a limit of detection of 8.94 µg L − 1 and a linear range of 30–700 µg L − 1 , validating the sensor's real‐world applicability. Additionally, structural and electronic parameter changes indicate robust molecular interactions, reinforcing the composite's potential as an efficient and selective CLM sensor for pharmaceutical and environmental monitoring.