doi:10.1038/nindia.2016.109 Published online 24 August 2016
Researchers have developed a new DNA sensor that can potentially lead to reliable and quick detection of leukemia1. Sensing is based on the change in electrical properties of the nano-sized electrode when it is exposed to nucleic acids like the DNA.
Caused by the active breakpoint cluster region (BCR)/ Abelson (ABL), chronic myeloid leukemia (CML) is a common form of blood cancer. Its detection and subsequent treatment are hampered by techniques that are imprecise and time consuming. DNA sensors, which can quickly detect specific nucleic acid sequences, are low-cost alternatives to existing, expensive ways of detection.
The researchers built an electrode by skillfully depositing an extremely thin layer of amino-functionalised silica-coated zinc oxide nano-assemblies on a glass substrate coated with indium tin oxide. They noticed a jump in electron transfer resistance of this nano electrode, first after immobilizing the probe DNA, and again, after hybridisation with complementary DNA. Picking signals from this change in electrical resistance, the researchers succeeded in detecting the BCR/ABL fusion gene — an important biomarker for the early detection of CML.
Studies also confirmed that the electron transfer resistance varied in proportion with the concentration of the complementary DNA, a property that is essential for a sensor of this kind. The sensor could also pick up the target DNA from a multitude of nucleic acids — another essential property for a medical diagnostic device. The researchers also validated the performance of the sensor by comparing its results with clinical samples of patients with CML. “We are working towards fabricating an on-line electrochemical DNA sensor in a single platform”, say the researchers.
1. Pandey, C. M. et al. Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for blood cancer detection. Anal. Chim. Acta. (2016) doi: 10.1016/j.aca.2016.07.024