Professor Kazuaki Sawada of the National Center for Geriatrics and Gerontology and colleagues at Toyohashi University of Technology have created a charge-couple device (CCD) array sensor that is sensitive to small changes in electric potential and microbeads on which antigen-antibody reactions take place. The combination of the CCD sensor and the microbeads has created a diagnostic sensing system for analysing blood and urine for early diagnosis of ailments including diabetes and Alzheimer’s disease.
The technology will enable the monitoring and diagnosis of diseases for which specific markers are known, using very small volumes of blood or urine. Specifically, this technology has detected amiloid beta-peptide, an agent responsible for Alzheimer’s disease.
Conventional protocols used to monitor antibody-antigen reactions employ fluorescent probes and detection of fluorescence with microscopic cameras. This process is time consuming because of the necessity to measure fluorescence from the probes and cannot be used to detect low concentrations of antigens. The CCD method detects minute changes in electric potential generated during an antigen-antibody reaction.
The CCD is 128 by 128 pixels and the sensitivity is enhanced using microbeads by increasing the available surface area. Multiple diseases could be diagnosed simultaneously by placing different antibodies on different sensing pixels.
The technology is due to be tested in a program on the daily control of diabetes and in future the application of the technology extended to the early diagnosis of Alzheimer’s and Parkinson diseases.
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