Highly Sensitive and Selective Electrochemical Detection of Dopamine using Hybrid Bilayer Membranes

The rapid and precise measurement of dopamine (DA) levels is of great benefit to unveil physiological and pathological processes. The electrochemical detection approaches feature fast DA response, but remain challenging at the moment to realize ultra-high sensitivity and selectivity to the trace amount of DA, especially in the presence of highly concentrated ascorbic acid (AA, the most common interferent in the human body). To address this issue, a negatively charged hybrid bilayer membrane (HBM) modified gold electrode was designed, which was only attractive to the positive DA but not the negative AA. As a result, this work managed to achieve an ultra-low detection limit of 0.41 pM DA under the interference of AA of 10(9) times higher concentration. Such an excellent performance is over three orders of magnitude better than previously reported electrochemical sensing methods, suggesting the promise of applying HBM functionalization in electrochemical and bio-sensing applications.