Background: A simple, rapid, low-cost and environmentally friendly method was developed to determine dopamine (DA) in the presence of ascorbic (AA) and uric acid (UA) based on a novel technique to prepare a graphene-chitosan (GR-CS) nanocomposite and modify it on the surface of carbon paste electrode (CPE). For our design, CS acts as a media to disperse and stabilize GR, and then GR plays a key role to selective and sensitive determination of DA.

Results: Under physiological conditions, the linear range for dopamine was determined from 1.00 x 10^-4 to 2.00 x 10^-7mol/L with a good correlation coefficient of 0.9961 in the presence of 1000-fold interference of AA and UA. The detection limit was estimated to be 9.82 x 10^-8 mol/L (S/N=3). In order to study the stability and reproducibility, GR/CS/CPE was suffered successive measurements in 10 times and then tested once a d for 30 d. The result exhibited 98.25% and 91.62% activities comparing with original peak current after 10-time measurements and 30-d store.

Conclusion: The GR/CS/CPE has wide linear concentration range, low detection limit, good reproducibility and stability, suggest that our investigations provide a promising alternative for clinic DA determination.