Facile Synthesis of Co9S8 Nanocages as an Electrochemical Sensor for Luteolin Detection

A novel Co9S8 nanocage was fabricated via a metalorganic frameworks engaged strategy. The morphology and structure of the resulting Co9S8 nanocage were carefully confirmed by scanning electron microscopy, powder X-ray diffraction, transmission electron microscope, and X-ray photoelectron spectroscopy. Then the as-synthesized Co9S8 nanocage material was immobilized on a glassy carbon electrode (GCE) and served as an efficient sensing platform for determination of luteolin. Under optimized conditions, the prepared Co9S8/GCE shows significant electrocatalytic activity toward the oxidation of luteolin. By comparison with GCE and CoS/GCE, the proposed Co9S8/GCE results in great improvement in the electrochemical response of luteolin. Meanwhile, the Co9S8 based-sensor presents an excellent linear relationship with the concentration of luteolin ranging from 0.01 to 20 μM. Then, the limit of detection based on S/N = 3 was estimated to be 0.8 nM. In addition, the Co9S8/GCE displays good repeatability, reproducibility, and selectivity. Finally, the simplicity and low cost of this sensor makes it possible to determination luteolin in actual sample with good accuracy and precision.