Low-cost screen-printed carbon sensors have been used to rapidly detect bacteria commonly found in wounds which may help in developing real-time medical devices.
The University of Strathclyde and NHS Ayrshire & Arran made use of sensitive portable electrochemical sensors to detect infections in clinical samples within half an hour, fatser than current hospital laboratory testing.
Detecting infection in clinical practice can be expensive and takes about 48 hours at least for best standard laboratory methods of detecting infection on wounds and bacterial identification.
In a collaboration with NHS Ayrshire & Arran clinicians, swabs and dressings were gotten from patients with diabetic-related foot ulcers. The samples were then measured with the aid of the novel sensor which shows that bacterial infection could be detected rapidly.
In the previous work that led to this clinical study, the sensors were utilized to detect Proteus mirabilis, one of the common types of bacteria found in wounds. The organism is usually detected in the gastrointestinal tract of humans and makes up part of the body’s normal microflora however, can cause disease in individuals who have compromised wounds or immune systems.
The peer-reviewed study, which won Best Paper Award at the annual World Congress on Electrical Engineering and Computer Systems Science in July, describes the real-time electrochemical detection of the pathogen, with the growth detected in laboratory tests one hour after sample inoculation.
The electrochemical technique is used to measure the electrical ‘impedance’ of a sample over a wide range of electrical signal frequencies, creating spectra formed by measuring the flow of current through the layer of bacteria at each frequency. Changes to these spectra with time can be assessed providing information about the microbiological content of the sample.
Healthcare-associated infections (HAI) are a significant threat to patient welfare, resulting in increased treatment times, costs, and illness. Wound infections are a common form of HAI.
Researchers believe the technology is capable of being integrated into a cost-effective real-time wound monitoring device that can rapidly detect infection and reduce the detection of wound infection and time on identifying wounds in clinical settings.
Aiden Hannah, a biomedical engineering researcher from the University who carried out this work, said: “Whilst a range of other bacteria have been detected using Electrochemical Impedance Spectroscopy, to the best of our knowledge this is first reported study of real-time Proteus mirabilis detection using a label-free, screen-printed carbon electrode.
“The ability of our low-cost sensors to rapidly detect the presence of infection in clinical wound samples highlights their potential for adoption into point-of-care infection monitoring devices. The ability to monitor infection status in real-time would enable earlier intervention and improved prognosis.”
