In earlier studies, these researchers demonstrated that the nanowires could detect generalized activation of this small number of T cells. The new report expands that work and shows the nanowires can identify activation from a single specific antigen even when there is substantial background "noise" from a general immune stimulation of other cells.
Describing the sensitivity of the system, senior author Tarek Fahmy, Yale assistant professor of biomedical engineering, stated: "Imagine I am the detector in a room where thousands of unrelated people are talking - and I whisper, 'Who knows me?' I am so sensitive that I can hear even a few people saying, 'I do' above the crowd noise. In the past, we could detect everyone talking - now we can hear the few above the many."
According to the authors, this level of sensitivity and specificity is unprecedented in a system that uses no dyes or radioactivity. Beyond its sensitivity, they say, the beauty of this detection system is in its speed - producing results in seconds - and its compatibility with existing CMOS electronics.
"We simply took direction from Mother Nature and used the exquisitely sensitive and flexible detection of the immune system as the detector, and a basic physiological response of immune cells as the reporter", stated postdoctoral fellow and lead author, Eric Stern. "We coupled that with existing CMOS electronics to make it easily usable."
The authors see a huge potential for the system in POC diagnostic centres in the United States and in underdeveloped countries where health care facilities and clinics are lacking. They claim it could be as simple as an iPod-like device with changeable cards to detect or diagnose disease. Importantly, Eric Stern noted that the system produces no false positives - a necessity for POC testing.
The authors suggest that in a clinic, assays could immediately determine which strain of flu a patient has, whether or not there is an HIV infection, or what strain of tuberculosis or coli bacteria is present. Currently, there are no electronic POC diagnostic devices available for disease detection. "Instruments this sensitive could also play a role in detection of residual disease after antiviral treatments or chemotherapy", stated Tarek Fahmy. "They will help with one of the greatest challenges we face in treatment of disease - knowing if we got rid of all of it."
The work resulted from collaboration between the laboratories of Tarek Fahmy and Mark Reed, the Harold Hodgkinson Professor of Engineering & Applied Science within the Yale Institute for Nanoscience and Quantum Electronics (YINQE). Mark Reed and biomedical engineering graduate student Erin Steenblock are also authors on the study that was funded by the Department of Defense, the National Institutes of Health, the Department of Homeland Security and the National Science Foundation.