Ultrasensitive monitoring of DNA damage associated with free radicals exposure using dynamic carbon nanotubes bridged interdigitated electrode array.

There are currently increasingly concerns over DNA damage related to free radicals due to their vital roles in human health, especially high-performance detection method. Herein, we report an ultra- sensitive monitoring of DNA damage associated with free radicals exposure using interdigitated electrode (IDE) array for the first time. The proposed IDE array was equipped with DNA-wrapped carbon nanotube-based bridges, which utilized the DNA damage mechanism due to the free radicals' attack and the efficient electrical detection nature of the interdigitated electrode. Experiments have been performed, and the results showed the device's capability for detecting DNA damage induced by multiple free radicals generated from different sources, including the Fenton reaction, UV radiation and cigarette smoke, showing the promising ability for DNA damage detection. In addition, the carbon nanotubes bridge-based interdigitated electrode sensor enabled different levels of sensing of DNA damage with great sensitivity and a wide detection range. It was illustrated that the ultrasensitive detection of free radicals generated from ultraviolet radiation (15 min - 125 min), cigarette smoke tar (1 μg/mL to 10 μg/mL) and Fenton reaction under different concentration of H2O2 (2.5 pM - 100 pM), have been detected successfully. Typically, the IDE array supports further performance improvement for the electrochemical detection in an ultrasensitive and high throughput route.