Electrochemical Detection of the P. Aeruginosa Virulence Factor Pyocyanin Using Nanochannel Devices

Nearly one in ten hospital-acquired infections is caused by Pseudomonas aeruginosa, a versatile bacterium that is found in nearly every environment on earth. Clinical identification of P. aeruginosa is often carried out by observation of bluish-green colonies after culturing samples overnight at 42 degrees Celsius. The unique bluish-green color of these bacteria is caused by pyocyanin, a virulence factor that causes oxidative stress in cells. We have developed a device that integrates both a working and reference electrode inside of a nanoscale constriction and used it to measure pyocyanin produced by P. aeruginosa in growth media. By utilizing square wave voltammetry, micromolar concentrations of pyocyanin were selectively detected in a complex liquid solution.