ZIF-8 Coupling with Reduced Graphene Oxide to Enhance the Electrochemical Sensing of Dopamine

A reduced graphene oxide@zeolitic imidazolate framework-8 (rGO@ZIF-8) based electrochemical sensor was developed and used for dopamine detection. ZIF-8 was rapidly prepared by zinc hydroxide nitrate (Zn-HDS, Zn ₅ (OH) ₈ (NO ₃ ) ₂ ·2H ₂ O) as precursor. Subsequently, rGO was introduced to enhance the performance of ZIF-8 (e.g., high carrier mobility, favorable stability), and a label-free electrochemical dopamine sensor based on the composite material was obtained with high specific surface area and better conductivity verified by Brunauer–Emmett–Teller surface analysis and electrochemical impedance spectroscopy, respectively. Consequently, rGO@ZIF-8 complex exhibited an admirable electrochemical catalytic performance. For determination of dopamine, the sensor behaves wide linear range from 2.0 × 10 ⁻⁶ to 1.4 × 10 ⁻⁴ mol l ⁻¹ and lower detection limit of 2.0 × 10 ⁻⁸ mol l ⁻¹ (S/N = 3). It also showed sufficient repeatability and durability due to the coordinated amplification effect of rGO and ZIF-8.