Simultaneous and sensitive detection of dopamine and acetaminophen at a glassy carbon electrode modified with a carbonized-ZIF-67/Super P nanocomposite†

The coexistence of dopamine (DA) and acetaminophen (AC) in living organisms leading to an unexpected mutual interference in electrochemical detection techniques demands a simultaneous, selective as well as simple and cost-effective approach for DA and AC. Herein, a novel nanocomposite was fabricated by integrating carbonized ZIF-67 (C-ZIF-67) with carbon black Super P (SP) and introduced onto a glassy carbon electrode (GCE) to form a highly sensitive electrochemical sensor (C-ZIF-67/SP/GCE) for the simultaneous determination of DA and AC. The well-prepared nanomaterial presents a polyhedral morphology interlaced on a reticulated chain. C-ZIF-67/SP/GCE shows excellent electrocatalytic activity towards the redox reactions of DA and AC in a dynamic linear range up to 100 μM, which could be attributed to the synergistic effect of the large specific surface area of C-ZIF67 and the excellent conductivity of SP. The limits of detection (LODs, S/N = 3) of 0.58 μM and 0.27 μM were obtained for DA and AC, respectively. Moreover, the developed sensor exhibited good reproducibility and long-term stability. The C-ZIF-67/SP/GCE was employed to analyze DA and AC biomedical samples and satisfactory recoveries were achieved. This approach provides a simple, easy and sensitive method to detect DA and AC simultaneously and selectively.