Programmed to detect proteins and E. coli, one of the deadly bacteria that can cause the human body to go into septic shock, the detector uses light to look for specific biomarkers (the tell-tale signs or indicators of a disease) that are as small as a few nanometers in size, or 1/1,000,000th of the thickness of a single human hair.
The rapid microarray detector looks at a small blood sample taken from a thumb or forefinger. The patient’s blood sample is then separated in a centrifuge so that a clinician can examine the plasma, the part of the blood sample where all the proteins are contained.
The sepsis detector uses photonic technology to make a clear and accurate diagnosis. The plasma sample flows over a microarray, a collection of tiny spots containing specific antibodies on a nanostructured gold slide. Two light beams are then shone through the full microarray, with one of them passing through the sample, while the other one goes through the clear part of the slide, acting as a reference. The beams passing through the biomarker and the clear regions on the slide are then checked for any changes in intensity.
“Depending on the amount and type of biomarker attached to each antibody, we obtain a unique image, a signature pattern if you like,” said Roland Terborg, project coordinator. “The image patterns tell us what is present in the plasma sample, which we then record with a CMOS sensor, the same technology used in a digital camera that converts light into electrons.”
Preclinical trials have already begun at the Vall d'Hebron University Hospital where the device has been in operation since 2018. Clinical trials are expected to take place at the end of 2019.
Current techniques for detecting sepsis, a condition that kills more than 20,000 people per day worldwide, can take hours or even days to produce the results and diagnosis. While bacteria need to reproduce in large quantities before an accurate determination can be made, a patient can often be waiting more than a day before a course of treatment can be determined. If caught early enough, patients can be treated for sepsis with simple antibiotics.
The detector could also possibly be extended to perform other types of disease screenings or multiple simultaneous diagnoses, especially those requiring a rapid detection of large numbers of biochemical targets (more than one million) on a single microarray.
Developed by the RAIS project (or scalable point-of-care and label-free microarray platform for rapid detection of sepsis), the project was coordinated by ICFO in Barcelona and is a success story for the Photonics Public Private Partnership.
The RAIS consortium received a grant of €2,988,572 ($3,333,528) from the EU via the H2020 program and was made up of partners from Spain, Switzerland, Germany, Belgium, the U.K., and Italy. RAIS was coordinated by ICFO, and oversaw the collaboration of the Ecole Polytechnique Federale de Lausanne, iXscient, Diesse, the Catalan Institute of Nanoscience and Nanotechnology, microTEC, Trinean, Hospital Vall d’Hebron, and Thermo Fischer Brahms.
Additional information may be found on the RAIS Project website.