Cancer biomarker detection using graphene-modified electrode
Authors: Stela Pruneanu, Florina Pogăcean, Lidia Măgerușan, Valentin Mirel
Keywords: electrochemical sensors, biomarkers, 8-hydroxy-2′-deoxyguanosine
Applications
Oxidative DNA damage is responsible for cancer development. The initiation and promotion of malignant cells are associated with chromosomal defects and oncogene activation by free radicals.
A common form of lesion is the formation of hydroxylated bases of DNA, considered an important element in chemical carcinogenesis. This detection platform has been designed to be used as a working electrode in experiments for the electrochemical detection of 8-hydroxy-2′-deoxyguanosine (8-OH-dG), an excellent biomarker of oxidative stress and a risk factor for a variety of diseases including cancer, diabetes and neurological disorders.
Innovative aspects
Oxidative stress is defined as the imbalance between the level of oxidation products and the antioxidant capacity of the body, being an important pathogenetic link with destructive potential and high prevalence in modern medicine.
Increased oxidative stress can lead to extensive damage to lipids, proteins and DNA, the process being implicated in ageing and the development of conditions such as atherosclerosis, cancer, diabetes, cardiovascular disease, Parkinson’s, cataracts, muscle degeneration, Alzheimer’s, rheumatoid arthritis, fragile X syndrome, chronic fatigue syndrome, muscular dystrophy, etc.
Various tests are available to measure the levels of human plasma antioxidants as possible presence of oxidation products. As these are dynamic, evolving systems, the interpretation of the results depends on the conditions under which the measurements are made. Therefore, to be accurate, the assessments must be complex and repeated. Detection of 8-OH-dG in urine is a non-invasive approach to assess the extent of oxidative DNA damage.
Technology
This sensing platform was developed by modifying the surface of a vitreous carbide electrode with a new type of graphene obtained by exfoliation of graphite under pulsed current in a 0.2 M ammonium sulfate solution.
Cyclic voltammetry and linear voltammetry measurements showed that vitreous carbon electrodes with the modified surface showed increased electrochemical sensitivity for the detection of 8-OH-dG. The modified electrode has been successfully applied in the detection of biomarker concentration in standard laboratory solutions and artificial urine.
Advantages
- Enhancement of some vitreous carbon electrodes by modifying them with graphene, thus facilitating the detection of 8-hydroxy-2′-deoxyguanosine, one of the predominant forms of free radical-induced oxidative damage in DNA and a biomarker of oxidative stress
- Low production costs