A micro E-DNA sensor for selective detection of dopamine in presence of ascorbic acid

In this paper, a novel method for selectively detection of dopamine（DA） in the interference of ascorbic acid（AA） is described. A nanometer-sized gold flower microelectrode（NGFME） is prepared by flame-etching and electrochemical deposition. The electrode tip was characterized by scanning electron microscope（SEM）. The NGFME is sized at about 100 μm and dimensions of thorns of the electrode were in nanometers. By modifying with DA aptamer on the surface, the prepared aptasensor can selectively detect DA even in the presence of high concentration AA. Experimental results show that this NGFME has no response to AA. As a comparison, the carbon fiber electrode without DA aptamer modification is unable to effectively detect DA in the presence of AA. The NGFME is easy-to-prepare, selective and sensitive for DA detection down to 25 μM. The electrode can be expected to detect DA in vivo and in real biological samples.