Highly selective trapping of enteropathogenic E. coli on Fabry–Pérot sensor mirrors

Untreated recycled water, such as sewage and graywater, will almost always contain a wide range of agents that are likely to present risks to human health, including chemicals and pathogenic microorganisms. The microbial hazards, such as large numbers of enteric pathogens that can cause gastroenteric illness if ingested, are the main cause of concern for human health. The presence of the enteropathogenic Escherichia coli (EPEC) serotype is of particular concern, as this group of bacteria is responsible for causing severe infant and travelers’ diarrhea, gastroenteritis and hemolytic uremic syndrome. A biosensing system based on an optical Fabry–Pérot (FP) cavity, capable of directly detecting the presence of EPEC within 5 min, has been developed using a simple micro-thin double-sided adhesive tape and two semi-transparent FP mirror plates. The system utilizes a poly(methyl methacrylate) (PMMA) or glass substrates sputtered by 40-nm-thick gold thin films serving as FP mirrors. Mirrors have been activated using 0.1 M mercaptopropionic acid, influencing an immobilization density of the translocated intimin receptor (TIR) of 100 ng/cm2. The specificity of recognition was confirmed by exposing TIR functionalized surfaces to four taxonomically related and/or distantly related bacterial strains. It was found that the TIR-functionalized surfaces did not show any bacterial capture for these other bacterial strains within a 15 min incubation period.

► The enteropathogenic Escherichia coli (EPEC) serotype is causing severe infant and travelers’ diarrhea, gastroenteritis and hemolytic uremic syndrome can be optically detected.
► A biosensing system based on an optical Fabry–Pérot mirrors functionalized for a highly selective trapping of EPEC within 5–15 min has been developed.
► The system utilizes glass substratum modified with gold thin films for Fabry–Pérot cavity.
► An immobilization density of the translocated intimin receptor (TIR) is in the range of 100 ng/cm2.
► The specificity of recognition is confirmed by exposing TIR functionalized surfaces to four taxonomically related and non-related bacterial strains.