Rapid and highly sensitive detection of pyocyanin biomarker in different Pseudomonas aeruginosa infections using gold nanoparticles modified sensor

Abstract

Successful antibiotic treatment of infections relies on accurate and rapid identification of the infectious agents. Pseudomonas aeruginosa is implicated in a wide range of human infections that mostly become complicated and life threating, especially in immunocompromised and critically ill patients. Conventional microbiological methods take more than three days to obtain accurate results. Pyocyanin is a distinctive electroactive biomarker for Pseudomonas aeruginosa . Here, we have prepared polyaniline/gold nanoparticles decorated ITO electrode and tested it to establish a rapid, diagnostic and highly sensitive pyocyanin sensor in a culture of Pseudomonas aeruginosa clinical isolates with high selectivity for traces of pyocyanin when measured in the existence of different interferences like vitamin C, uric acid, and glucose. The scanning electron microscopy and cyclic voltammetry techniques were used to characterize the morphology and electrical conductivity of the constructed electrode. The determined linear range for pyocyanin detection was from 238 μM to 1.9 μM with a detection limit of 500 nM. Compared to the screen-printed electrode used before, the constructed electrode showed a 4-fold enhanced performance. Furthermore, PANI/Au NPs/ITO modified electrodes have demonstrated the ability to detect pyocyanin directly in Pseudomonas aeruginosa culture without any potential interference with other species.

Pseudomonas aeruginosa Biofilms

“…However, those methods are time-consuming as they require the target molecules/proteins to be purified from bacterial cultures. Recently, nanoparticles have been developed to allow rapid identification of pyocyanin [ 131 ] and LasA protease [ 132 ] with high sensitivity even in the presence of other species within cell cultures. Gold nanoparticles (Au NPs) deposited onto indium tin oxide electrodes was able to enhance the detection of pyocyanin at a concentration as low as 40 µM as compared to the minimum 80 µM of pyocyanin detected using unmodified electrodes [ 131 ].…”

“…Recently, nanoparticles have been developed to allow rapid identification of pyocyanin [ 131 ] and LasA protease [ 132 ] with high sensitivity even in the presence of other species within cell cultures. Gold nanoparticles (Au NPs) deposited onto indium tin oxide electrodes was able to enhance the detection of pyocyanin at a concentration as low as 40 µM as compared to the minimum 80 µM of pyocyanin detected using unmodified electrodes [ 131 ]. Encapsulating the Au NPs with a thin layer of polyaniline hydrochloride (PANI) forming PANI/Au core-shell NPs increased the sensitivity of the PANI/Au NPs-modified electrodes towards pyocyanin down to 36 µM, which could accelerate the diagnostic process, achieving effective treatments and prevention of chronic infections [ 131 ].…”

Application of Conducting Polymer Nanostructures to Electrochemical Biosensors

“…Elkhawaga et al have prepared PANI/Au NPs/ITO electrode as PYO sensor in a culture of P. aeruginosa. The results indicated that PANI/Au NPs/ ITO electrode is more sensitive toward PYO biomarker than either bare ITO electrode or Au NPs/ITO electrode with LOD of 500 nM [42]. The enhancement of the electrochemical activity of PANI/Au NPs/ITO modified electrode towards the PYO related to the presence of positive charges on its surface that could enhance the mass transfer rate of the negatively charged PYO based on the electrostatic attraction force.…”

Emerging Technologies for the Electrochemical Detection of Bacteria

“…The commercially‐available Zensor TE100 SPE showed an excellent correlation between electrical signal loss and the viability of PA cells after antibiotic (colistin sulfate) exposure [ 73b,75 ] and to monitor the electrochemical response of PYO generated by bacteria in the presence of various amino acids ( Figure 8 A,B). [ 73b ] Maximal current peaks were reduced by ≈68% and 82% when exposed to colistin sulfate, a last‐resort treatment for cases of MDR PA infection.…”

“…[ 73b ] Maximal current peaks were reduced by ≈68% and 82% when exposed to colistin sulfate, a last‐resort treatment for cases of MDR PA infection. [ 73b,75,76 ] Other EC studies for PYO‐tracing using SPEs as the primary tech include the commercially available SPE, Dropsens C223AT with a 1.6 mm Au WE, as well as Au CE and Ag RE. [ 64,74 ] Similarly to the Zenzor TE100, Dropsens C223AT SPEs are highly adaptable, having a low‐cost, high conductivity, and allow various electrochemical methods such as SWV, CV, DPV, thus being optimal for the electrochemical sensing of PYO.…”