Rapid Synthesis of ZIF-8 Nanocrystals for Electrochemical Detection of Dopamine

Zeolitic imidazolate framework-8 is obtained rapidly within 30 min via ultrasonic-assisted solvothermal method. The structure, elemental composition and morphology are investigated by X-ray diffraction, energy-dispersive X-ray detector, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller. The results show that Zeolitic imidazolate framework-8 nanocrystals possess cubic sodalite-related structure and provide more active sites for adsorption. Furthermore, the prepared Zeolitic imidazolate framework-8 nanocrystals have been examined for the electrochemical sensor of dopamine using cyclic voltammetry and differential pulse voltammetry techniques. The electrochemical studies demonstrate that the modified electrode displayed enhanced catalytic activity in the process of oxidation of dopamine when the working potential is −100 mV. Additionally, we use the sensor to detect dopamine linearly over a concentration range from 5.0 × 10−8 to 2.0 × 10−5 M with a lower detection limit of 1.95 × 10−7 M (S/N = 3). Importantly, Zeolitic imidazolate framework-8 nanocrystals modified electrode showes favorable anti-interference ability and long-term stability.