Simple and inexpensive electrochemical paper-based analytical device for sensitive detection of Pseudomonas aeruginosa

Pseudomonas aeruginosa (PA) is an opportunistic pathogen responsible for several diseases in humans and it is one of the main causes of hospital-acquired infections exhibiting a high drug-resistance profile. Hence, the rapid detection of pathogenic infections caused by bacteria in biofluids from patients or screening contaminated surfaces/utensils is of the utmost importance to healthcare, especially in places with high clinical demand and in resource-limited settings. Herein, we report a portable, selective, and very sensitive method (ranging nmol L-1 concentrations) for PA detection in human saliva and contaminated surfaces, without any sample preparation or separation steps. We used an inexpensive and disposable electrochemical paper-based analytical device (ePAD) for detecting pyocyanin (PYO), a key biomarker virulence factor that is unique for this pathogen. Additionally, we followed PA growth of two virulent strains, PA14 and PAO1, and found a high correlation between the electrochemically detected PYO levels and the optical density values of PA colony forming units (CFU), demonstrating the usefulness of the device for monitoring the bacterial growth and the early detection of PA infection in several relevant applications.