A rapid and sensitive integrated system to test simultaneously for specific cardiac biomarkers in finger prick amount of blood has been developed by scientists at Singapore’s Institute of Microelectronics (IME).
The silicon-based integrated system’s features could help physicians quickly arrive at the right diagnosis for timely medical intervention in patients suspected of having heart attacks-particularly individuals who do not show obvious signs of chest pains or shortness of breath, according to researchers at IME, one of the research institutes sponsored by Singapore’s A*STAR (Agency for Science, Technology and Research).
The IME-developed cardiac biomarker testing system significantly cuts the time needed for sample preparation and analysis to just 45 minutes from the six hours typically required for the conventional testing platform known as ELISA (Enzyme-linked Immunosorbent Assay).
Because of its multiplexing capability – measuring several cardiac biomarkers simultaneously-the new system contributes to the detail and certainty of diagnosis.
The IME-developed system is a label-free technology that uses semiconducting silicon nanowires (SiNWs) as biosensors. The working principle behind the nanowire biosensors is the field-effect transistor, which is responsible for generating a measurable electrical response when specific antibody-antigen interactions occur on the nanowire surface.
Specific antibodies that are immobilized onto the nanowire surface will elicit antibody-antigen interactions when allowed to come into contact with the variety of charged cardiac biomarkers. Released into the blood when the heart is injured, cardiac protein biomarkers such as troponin-T and creatinine kinases, are the basis of medical tests of patients in which a heart attack is suspected.
The IME-developed system is a label-free technology – thus eliminating the tagging step, thereby saving time and reagent consumption costs. In classical biochemical methods, the tagging of a fluorescent dye to the targeted analyte is used to detect and quantify the targeted analyte.