Real-time bacterial detection with an intracellular ROS sensing platform

Publication date: Available online 19 June 2019Source: Biosensors and BioelectronicsAuthor(s): J.M. Hicks, R. Halkerston, N. Silman, S.K. Jackson, J.W. Aylott, F.J. RawsonAbstractReactive oxygen species are highly reactive molecules that as well as being ubiquitously expressed throughout the body, are also known to be involved in many diseases and disorders including bacterial infection. Current technology has limited success in the accurate detection and identification of specific reactive oxygen species. To combat this, we have developed an electrochemical biosensor that is constructed from single walled carbon nanotubes that have been immobilised on an indium tin oxide surface functionalised with osmium-based compound. This sensor was integrated within mouse macrophage cells (RAW 264.7) with multiple serotypes of bacteria used to initiate an immune response. Intracellular hydrogen peroxide was then measured in response to the interaction of the lipopolysaccharides, present on the outer wall of Gram-negative bacteria, with the Toll-like Receptor 4. Additional controls of n-acetylcysteine and sodium pyruvate were implemented to prove the specificity of the sensor towards hydrogen peroxide. The sensors were found to have a lower limit of detection of 368 nM hydrogen peroxide. An increase in intracellular hydrogen peroxide was detected within 3 seconds of interaction of the bacteria with the macrophage cells. This low limit of detection combined with the rapid response of th...
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research