Electrochemical Sensing of Amoxicillin Drug-Assisted Uropathogenic E. coli Bacteria Using Gold Nanostructures—A Preliminary Study

The present study focuses on the electrochemical sensing of amoxicillin (AMX, as a model antibiotic drug) and its interaction with Uropathogenic E. coli (UPEC) bacteria (as a model pathogen) under physiological conditions. The electrochemical sensor probe is formulated by nanostructured gold wires (AuNWs) embedded in a carbon nanofiber–chitosan (CNF-CHIT) matrix. The synthesis of AuNWs is characterized by scanning electron microscopy (SEM), UV-Visible spectrophotometry, and X-ray photoelectron spectroscopy (XPS). The CNF-CHIT/AuNW-modified system is characterized by SEM and XPS. Initially, the CNF-CHIT/AuNW electrode was utilized for the sensing of AMX; later, in the antibiotic drug-assisted sensing of UPEC, i.e., in the presence of AMX, the interaction of UPEC was studied. The modified electrode showed appreciable sensitivity for AMX sensing; also, the interaction of AMX with UPEC is studied at two different conditions. One, at a fixed concentration of AMX (100 µM) and different concentrations of UPEC bacteria (0.6–1.2 × 106 CFU/mL), and another with incubation time (1 h–1 h 35 min) for bacterial reaction. The electrochemical antimicrobial resistance developed by UPEC, which is inherent in the sensing of AMX, is the key concept for the detection of pathogens.