Graphene Based Biosensors for Detection of Neurotransmitters

In addition use of illegal drugs namely heroin, cocaine and nicotine blocks the dopamine uptake and increase the risks of depression and drug addiction. Dopamines being electrochemically active species, several electrochemical techniques are employed to detect even low levels of dopamine. The major problem dealt with this electrochemical detection is that the presence of the interfering compounds such as uric acid and ascorbic acid. Uric acid is produced as a result of metabolism of purine whereas the ascorbic acid acts as reducing agent and helps in protection against biological oxidation process. Since ascorbic and uric acids have similar oxidation potential they usually overlap the dopamine oxidation peaks and hence make difficult to distinguish separately. Moreover the oxidation of these interfering compounds fouls the working electrode surface in electrochemical process and leads to poor sensor performance. Hence surface modification of electrode becomes essential for effective and sensitive detection of dopamine at low concentration with improved sensing range.