A Highly Sensitive Amperometric Sensor for Monitoring Sulfide and Microbiologically Influenced Corrosion

Pang, Xin (Natural Resources Canada) | Shi, Chao (Natural Resources Canada) | Arafin, Muhammad (Natural Resources Canada) | Zhang, Ruby (Natural Resources Canada)



Microbiologically influenced corrosion (MIC) has been considered a significant factor contributing to oil and gas pipeline failures. This type of corrosion results from the activities of microorganisms in the biofilms formed on metal surfaces. The in-situ monitoring of MIC is very challenging as it requires a combination of microbiological, surface analytical and electrochemical methods. Sulfate-reducing bacteria (SRB) are considered a predominant cause of MIC and they reduce sulfate to sulfide through anaerobic respiration. Thus the microbial corrosion can be monitored through the detection of biogenic sulfide resulting from the SRB activities. In this paper, an amperometric sensor was constructed for on-line detection of sulfide. Single-walled carbon nanotubes (SWCNTs) functionalized with a conducting polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) were used to facilitate signal transduction. The SWCNT-PEDOT-PSS modified glassy carbon electrode (GCE) sensor exhibited a large linear detection range, short response time, and high sensitivity for detection of sulfide, through direct oxidation of the sulfide without the assistance of any enzyme and mediator. The results paved the way for the development of on-line biosensors for fast and reliable monitoring of MIC related to SRB activities.