Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

Abstract

Pyocyanin is a virulence factor uniquely produced by the pathogen Pseudomonas aeruginosa. The fast and selective detection of pyocyanin in clinical samples can reveal important information about the presence of this microorganism in patients. Electrochemical sensing of the redox-active pyocyanin is a route to directly quantify pyocyanin in real time and in situ in hospitals and clinics. The selective quantification of pyocyanin is, however, limited by other redox-active compounds existing in human fluids and by other metabolites produced by pathogenic bacteria. Here we present a direct selective method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between −1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58–0.82 V that is unaffected by other redox-active interferents. The linear quantification of pyocyanin has an R2 value of 0.991 across the clinically relevant concentration range of 2–100 µM. The proposed method was tested on human saliva showing a standard deviation of 2.5% ± 1% (n = 5) from the known added pyocyanin concentration to the samples. This inexpensive procedure is suggested for clinical use in monitoring the presence and state of P. aeruginosa infection in patients.

Direct and Rapid Electrochemical Detection of Pseudomonas aeruginosa Quorum Signaling Molecules in Bacterial Cultures and Cystic Fibrosis Sputum Samples through Cationic Surfactant‐Assisted Membrane Disruption

“…For PYO, the first pronounced peak at the negative potential reflects the oxidation of PYO whereas the second peak at a high potential is responsible for the polymerization of this compound (Figure a). The negative peak of PYO has been overlapped by some endogenous compounds in biological fluids including human saliva . PQS also has two oxidation peaks, reflecting the presence of –NH in the phenol ring .…”

“…Single analyte detection has a significant limitation in clinical pathogen detection due to the genetic heterogeneity that exists among PA . Therefore, the detection of PYO alone as described in Alatraktchi et al . using disposable screen‐printed gold electrodes and Webster et al .…”

“…CTAB, which removes the lipids of the cell membranes, thus obviating the time‐consuming solvent and solid phase extraction step, is advocated for this purpose considering its low cost and availability. The BDD electrode is not subjected to any fouling during the analysis, a classical problem associated with screen‐printed electrodes (SPE) or other carbon based materials.…”

Electrochemical Detection of Pyocyanin as a Biomarker for Pseudomonas aeruginosa: A Focused Review

“…In the following years, several pyocyanin detection approaches were published using disposable screen-printed electrochemical electrodes [ 25 , 30 , 31 , 32 ]. The sensors were single-used and it was argued that the disposability of the electrodes makes them ideal for irreversible electrochemical measurements such as targeting the phenolic oxidation potential of pyocyanin.…”

Connecting Biology to Electronics: Molecular Communication via Redox Modality

“…PYO is also a biological signaling molecule that appears to be engaged in redox‐based signaling . Thus, redox‐probing that can access information of the presence of PYO and its redox‐state should provide important insights of biological activities (e.g., of Pseudomonas infections) …”