One-step synthesis of 2D@3D hollow Prussian blue analogue as a high-performance bifunctional electrochemical sensor

Prussian blue analogues (PBAs) are a family of classic coordination polymers. They have been widely applied in various fields including electrochemical sensors. Cubic nanoparticle structure is their common morphology. It is still a great challenge to design a hollow and two-dimensional (2D) PBA material. Of course, it will be a significant surprise if a hollow cube and 2D sheet can be integrated into one material. In this work, we designed a simple one-step synthetic strategy and resolved the above difficulty, wherein a hollow cubic PBA covered by 2D ultrathin nanosheets was successfully constructed, namely hollow tremella-like PBA (HTPBA). Furthermore, Ni foam (NF) as a substrate was introduced to obtain a self-supporting HTPBA/NF-12 electrode. HTPBA/NF-12, as a bifunctional electrochemical sensor electrode, exhibited distinguished catalytic performance towards glucose and nitrite, including remarkable selectivity, reproducibility, sensitivity for glucose (21 410 mu A mM(-1) cm(-2)) and nitrite (1248 mu A mM(-1) cm(-2)), wide linear range of 2-1250 mu M and 5-3380 mu M, along with low detection limit of 0.056 mu M and 0.38 mu M, respectively. More importantly, HTPBA/NF-12 electrodes possessed good reusability and practicability even in goat serum. In this study, we developed a simple and effective strategy to fabricate 2D@3D PBA material with excellent electrocatalytic activity and provide a totally new viewpoint in the PBA sensing field.

Automated summary

In this study, a simple one-step synthetic strategy was designed to successfully construct a hollow cubic Prussian blue analogue (PBA) covered by 2D ultrathin nanosheets, namely hollow tremella-like PBA (HTPBA). Furthermore, a self-supporting HTPBA/NF-12 electrode was obtained by introducing Ni foam (NF) as a substrate. The HTPBA/NF-12 electrode exhibited distinguished catalytic performance towards glucose and nitrite detection, including remarkable selectivity, reproducibility, sensitivity, wide linear range, and low detection limit.