NiCoZn Oxide Nanocages on Reduced Graphene Oxide Nanosheets for the Electrochemical Detection of Luteolin

Mixed metal oxides derived from a metal–organic framework (MOF) sacrificial template take advantage of the original morphology of MOFs, excellent electrocatalytic properties, mesoporous structure, and more active sites and transport channels, which is favorable to construct a high-performance electrochemical sensor. Here, polyhedral CoZn-MOFs are synthesized by precipitation at room temperature, and then they are etched using Ni2+ to obtain hollow polyhedral NiCoZn hydroxide (NiCoZn-OH) nanocages. After self-assembly with graphene oxide (GO) nanosheets and annealing, the hollow polyhedral NiCoZn mixed metal oxide/reduced graphene oxide (NiCoZnOX/rGO) mixture with a size of ∼700 nm is obtained and used for electrochemically detecting luteolin (LU), which shows a high sensitivity (7.16 μA·μM–1·cm–2 in 0–60 μM) and a low limit of detection (64 nM, S/N = 3). Moreover, it has excellent selectivity in the presence of ascorbic acid and is successfully used to detect LU in diluted human urine, indicating a great potential in clinical applications.