Highly Sensitive Electrochemical Dopamine Sensor from Poly(diallyldimethylammonium chloride)-Functionalized Graphene Nanoribbon/Gold Nanoparticle Nanocomposite.

A novel graphene oxide nanoribbon/poly(diallyldimethylammonium chloride)/gold nanoparticle (GONR/PDDA/AuNP) nanocomposite was synthesized successfully and used for the sensitive detection of dopamine. The GONR/PDDA/AuNP nanocomposite was characterized by transmission and scanning electron microscopy. The electrochemical sensor based on GONR/PDDA/AuNP nanocomposite. was studied by cyclic voltammetry and electrochemical impedance spectroscopy. Experimental parameters such as GONR/PDDA concentration, volume ratio of GONR/PDDA to AuNP, scan rates, and pH were studied to investigate their effect on peak currents. Under optimal conditions, the GONR/PDDA/AuNP-based sensor exhibited excellent electrocatalytic activity for the detection of dopamine with a wide linear range from 9.99 x 10(-8) to 8.69 x 10(-4) M and a low detection limit of 3.33 x 10(-8) M. Moreover, the proposed sensor exhibits high sensitivity, good reproducibility, and stability, and could therefore potentially be applied in other bioanalytical systems.