DNA-based fiber optic sensor for direct in-vivo measurement of oxidative stress

Abstract

Oxygen is one of the most significant elements for life because almost all living organisms utilize oxygen for respiration and energy generation. However, some derivatives of oxygen including free radicals called reactive oxygen species (ROS) are detrimental and cause several diseases such as neurodegeneration, diabetes, cancer and atherosclerosis. Oxidative stress is essentially an inability of our body to counteract or detoxify the harmful effects of ROS through neutralization by antioxidants. Till date direct in-vivo measurements of oxidative stress are challenging. In this work, we have developed a novel 2,7-dichlorodihydrofluorescein (DCFH) impregnated genomic DNA-based biomaterial, which is completely insoluble in water and forms excellent thin film layers on optical fiber tips. The biomaterial-sensitized fiber tip fluoresces brightly in the proximity of ROS as the entrapped DCFH is oxidized to highly fluorescent DCF. We have demonstrated that an indigenously developed biomaterial-sensitized optical fiber tip can work as an efficient ROS/oxidative stress sensor in an aqueous medium as well as in the blood phantom (hemoglobin solution). A preclinical study on the minimally invasive direct in-vivo oxidative stress detection in mice model has also been successfully demonstrated.