Iranian researchers from Nanobiotechnology Department of the University of Tehran designed a nanosensor that has the highest reported value of sensitivity in the diagnosis of cancer.
The nanosensor enables diagnosis of cancer in its early stages through a fast, simple and cheap method.
The presence of DNA chains caused by cellular death in blood is a very good opportunity to detect them and to determine the changes in methylation to obtain early diagnosis of cancer.
According to Mehdi Dadmehr, one of the researchers, very low concentration of DNA in blood is one of the most important challenges for the detection of the changes, which requires a very sensitive detection system. Normal methods that are currently used all over the world are usually based on DNA proliferation after pretreatment, which results in the degradation of over 90% of DNA during the test.
In this research, the possibility to detect changes in methylation and even the percentage of methylation in more accurate manner has been provided by using a nanosystem based on fluorescent probe. The nanoysystem has very high sensitivity to the extent that it detects concentrations of DNA at about 0.3 femtomolar (3*10-16). This amount has so far been reported as the highest value of detection limit in comparison with all other methods being used across the world.
Iron oxide magnetic nanoparticles with gold coating have been used in the production of the nanosensor. Dadmehr explained the advantages of this research, and said, “In addition to enabling early diagnosis of cancer, the nanosensor facilitates target gene-therapy of the cancer by detecting the type of the methylized gene.”
Results of the research have been published in Biosensors and Bioelectronics, vol. 60, issue 1, April 2014, pp. 35-44.