Facile synthesis of Prussian blue nanocubes/silver nanowires network as a water-based ink for the direct screen-printed flexible biosensor chips

The large-scale fabrication of nanocomposite based biosensors is always a challenge in the technology commercialization from laboratory to industry. In order to address this issue, we have designed a facile chemical method of fabricated nanocomposite ink applied to the screen-printed biosensor chip. This ink can be derived in the water through the in-situ growth of Prussian blue nanocubes (PBNCs) on the silver nanowires (AgNWs) to construct a composite nanostructure by a facile chemical method. Then a miniature flexible biosensor chip was screen-printed by using the prepared nanocomposite ink. Due to the synergic effects of the large specific surface area, high conductivity and electrocatalytic activity from AgNWs and PBNCs, the as-prepared biosensor chip exhibited a fast response (<3 s)， a wider linear response from 0.01 to 1.3 mM with an ultralow LOD=5 µm, and the ultrahigh sensitivities of 131.31 and 481.20 µA mM⁻¹ cm⁻² for the detections of glucose and hydrogen peroxide (H₂O₂), respectively. Furthermore, the biosensor chip exhibited excellent stability, good reproducibility and high anti-interference ability towards physiological substances under a very low working potential of −0.05. Hence, the proposed biosensor chip also showed a promising potential for the application in practical analysis.