Yang-Rae Kima, Sungyool Bonga, Yeon-Joo Kanga, Yongtak Yanga, Rakesh Kumar Mahajanb, Jong Seung Kimc,*, Hasuck Kima,*
a Department of Chemistry, Seoul National University, Seoul 151-747, Republic of Korea
b Department of Chemistry, Guru Nanak Dev University, Amritsar 143005, India
c Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea
*Corresponding authors : Jong Seung Kim, Hasuck Kim
Dopamine plays a significant role in the function of human metabolism. It is important to develop sensitive sensor for the determination of dopamine without the interference by ascorbic acid. This paper reports the synthesis of graphene using a modified Hummer's method and its application for the electrochemical detection of dopamine. Electrochemical measurements were performed at glassy carbon electrode modified with graphene via drop-casting method. Cyclic voltammogram of ferri/ferrocyanide redox couple at graphene modified electrode showed an increased current intensity compared with glassy carbon electrode and graphite modified electrode. The decrease of charge transfer resistance was also analyzed by electrochemical impedance spectroscopy. The capacity of graphene modified electrode for selective detection of dopamine was confirmed in a sufficient amount of ascorbic acid (1 mM). The observed linear range for the determination of dopamine concentration was from 4 μM to 100 μM. The detection limit was estimated to be 2.64 μM.
Dopamine; Ascorbic acid; Graphene; Cyclic voltammetry; Electrochemical impedance spectroscopy