Abstract
The availability of clean drinking water is a significant problem worldwide. Many technologies exist for purifying drinking water, however, many of these methods require chemicals or use simple methods, such as boiling and filtering, which may or may not be effective in removing waterborne pathogens. Present methods for detecting pathogens in point-of-use (POU) sterilized water are typically time prohibitive or have limited ability differentiating between active and inactive cells. This work describes a rapid electrochemical sensor to differentially detect the presence of active Escherichia coli (E. coli) O157:H7 in samples that have been partially or completely sterilized using a new POU electrocatalytic water purification technology based on superradicals generated by defect laden titania (TiO2) nanotubes. The sensor was also used to detect pathogens sterilized by UV-C radiation for a comparison of different modes of cell death. The sensor utilizes immunomagnetic bead separation to isolate active bacteria by forming a sandwich assay comprised of antibody functionalized secondary magnetic beads, E. coli O157:H7, and polyguanine (polyG) oligonucleotide functionalized secondary polystyrene beads as an electrochemical tag. The assay is formed by the attachment of antibodies to active receptors on the membrane of E. coli, allowing the sensor to differentially detect viable cells. Ultravioloet (UV)-C radiation and an electrocatalytic reactor (ER) with integrated defect-laden titania nanotubes were used to examine the sensors’ performance in detecting sterilized cells under different modes of cell death. Plate counts and flow cytometry were used to quantify disinfection efficacy and cell damage. It was found that the ER treatments shredded the bacteria into multiple fragments, while UV-C treatments inactivated the bacteria but left the cell membrane mostly intact.
Highlights
Enterohemorrhagic Escherichia coli (E. coli) serotype O157:H7 is a highly infectious food and waterborne bacteria that effects populations worldwide [1]
The novel focus of this paper is to demonstrate that the electrochemical sensor could be paired with electrocatalytic reactor (ER) sterilization
3.1. and Exposure of E. coli to ER and UV treatments both resulted in cell death, as shown from the
Summary
Enterohemorrhagic Escherichia coli (E. coli) serotype O157:H7 is a highly infectious food and waterborne bacteria that effects populations worldwide [1]. Antimicrobial use against E. coli O157:H7 causes the cell to release Shiga toxins that cause bloody diarrhea, and in some severe cases, hemolytic. Plate counting is the gold standard method for detecting E. coli O157:H7 [4,5]. This method is not ideal for POU because it requires long incubation times (2–3 days) and is labor intensive. Another common approach identifies bacteria nucleic acids by attaching a synthetic oligonucleotide probe or primer to the complimentary target sequence for detection [6]. Polymerase chain reaction (PCR) is used to amplify Shiga toxin producing Escherichia coli (STEC) genes by replicating the gene sequence
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
