A simple label-free electrochemical aptasensor for dopamine detection

A simple, label-free electrochemical biosensor based on a dopamine (DA) DNA aptamer immobilized on a Au electrode through the Au-S bond was developed. Methylene blue (MB) was used as the intercalating probe, and DA was sensitively and selectively detected. The developed electrochemical DA aptasensor showed a good linear response to DA from 5-150 nmol L-1 as well as having a low detection limit of 1.0 nM (S/N = 3). The biosensor also exhibited satisfactory selectivity and could be successfully used to detect DA in human blood, suggesting that the aptasensor is a promising application for the analysis of DA in real clinical samples.