Japan Research Institute develops DNA detection technology using conductive diamond
Schematic diagram of the detection principle [Nikkei BP News Agency] The Japan Industrial Technology Research Institute has developed a DNA alignment detection technology using conductive diamond. "Compared with previous detection techniques, it has successfully achieved a sensitivity of 2 digits or even 3 digits" (the Institute). The detection sensitivity was 2 pM (picomolar) / L.
The structure developed this time is to make a fine "knife mountain" with a 10 mm interval on the surface of the conductive diamond, and to implant the probe DNA on the tip of these knives. In the conventional DNA detection technique, the structure in which probe DNA is disposed on an electrode using gold (Au) and carbon is the most common.
When the measurement target DNA is combined with the probe DNA to form a double strand, the ion current flowing through the conductive diamond is reduced. The presence or absence of a reaction can be detected by a change in current. The reason why the ion current is reduced is that the gap between adjacent probes is narrowed after the double-strand is formed, and the gap through which the ion current can pass is small.
Since the bound double strand is separated by increasing the temperature, the probe DNA can be reduced to a single strand. It has been confirmed that stable detection can be performed after repeating 100 operations.
The Research Institute is striving to apply it to medical and food safety, and plans to further improve sensitivity and promote the development of the best sensor for measuring objects.