Pseudomonas aeruginosa imprinted polydopamine@graphene-coated pencil graphite electrode for selective bacterial detection

Abstract

In this study, molecularly imprinted polydopamine films were prepared on graphene oxide-modified graphite electrodes by chemical oxidation of dopamine in the presence of template molecules of P. aeruginosa. The electrodes were electrochemically characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The electrodes were also chemically characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). According to the results, films were successfully deposited on the electrodes and displayed increased electrical conductivity in combination with graphene oxide. After template removal, selective cavities for P. aeruginosa were exposed. The analytical performances of the electrodes were tested using DPV in the concentration range of 102 – 108 CFU/mL. Meanwhile, the limit of detection (LOD) and limit of quantification (LOQ) were calculated as 1.85 CFU/mL, and 6.50 CFU/mL, respectively. The sensor was also highly selective against P. aeruginosa in comparison to Escherichia coli, Staphylococcus aureus, and Bacillus subtilis being evaluated as potential interfering competitors.