Detection of Pseudomonas aeruginosa infection using a sustainable and selective polydopamine-based molecularly imprinted electrochemical sensor

Abstract

Pyocyanin, a redox-active secondary metabolite produced by Pseudomonas aeruginosa, serves as a crucial virulence factor. Detection and quantification of pyocyanin can aid early diagnosis of infection. A selective and sensitive molecularly imprinted electrochemical sensor was constructed by using a green polymerization technique to deposit an ultrathin polydopamine film on an electrode modified with gold nanoparticles and chitosan. Target recognition was facilitated by specific binding sites within the imprinted polymer matrix that are complementary to the structure of pyocyanin. Various techniques, including cyclic voltammetry, electrochemical impedance spectroscopy, and square wave voltammetry, were employed to characterize the electrochemical behavior of the sensor. We investigated the influence of fabrication components, including chitosan concentration, monomer concentration, electro-polymerization conditions, pH, and rebinding time. Demonstrating a high degree of specificity and sensitivity, the sensor showcased a broad linear detection range of 1–100 µM and a low detection limit of 0.74 µM for pyocyanin. Moreover, the sensor successfully detected pyocyanin in real bacterial culture samples, exhibiting a recovery of the spiked standard ranging from 93 to 103 %. The electrochemical sensor displayed satisfactory stability lasting for at least 5 weeks. We demonstrated the sensor's applicability for clinical measurements by detecting pyocyanin in infected burn wounds using an ex vivo porcine skin model. Leveraging the synergistic advantages of molecularly imprinted polymer and the specific redox window for pyocyanin detection, the electrochemical sensor presents a promising approach for early-stage infection identification, thus contributing to enhanced treatment and more effective healthcare for patients.