MOF-derived N-doped nanoporous carbon framework embedded with Pt NPs for sensitive monitoring of endogenous dopamine release

A Pt NPs encapsulated hollow N-doped carbon framework was constructed by calcinating sandwich-like zinc imidazole framework (ZIF)-67 in N-2 atmosphere, and employed for electrochemical detection of dopamine. The morphology and element distribution of this framework was characterized by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The MOF-derived N-doped nanoporous carbon framework can take advantage of the nanoporous features from carbon structures, while Pt NPs maintained good dispersity during calcination. Furthermore, the relevant electrochemical performances were evaluated by amperometry and differential pulse voltammetry (DPV), and the results confirmed that such a structure will robustly promote the electron conduction and mass transfer of dopamine (DA), allowing the quantitative determination of DA with a wide linear range, a low limit of detection (LOD), a high sensitivity and a good selectivity. Based on these observations, the Pt NPs encapsulated hollow N-doped carbon framework modified glassy carbon electrode (CN@Co/Pt/Co-GCE) was further utilized to monitor the endogenous DA released from C6 cells by extracellular K+ stimulation.