Highly catalytic Prussian blue analogues and their application on the three-dimensional origami paper-based sweat sensors

Abstract

Prussian blue analogues (PBAs) are promising materials due to their rich active sites and straightforward synthesis. However, their limited conductivity and electron transfer inefficiency hinder practical applications. This study utilizes a simple one-pot synthesis approach to produce a tungsten-disulfide (WS₂) and iron-cobalt Prussian blue analogue composite (WS₂-PBA), enhancing conductivity and electron transfer rate performance. Through the inclusion of sodium citrate into the solution, the S-edge site concentration of WS₂ increases. This augmentation introduces additional active sites and defects into the catalyst, enhancing its catalytic activity. The effectiveness of the WS₂-PBA 3D-Origami paper device for lactate detection in sweat is also evaluated for biomedical applications. The device demonstrated a robust relationship between the lactate concentration and current intensity (R² = 0.997), with a detection limit of 1.83 mM. Additionally, this platform has successfully detected lactate in clinical sweat, correlating with the high-performance liquid chromatography test results, suggesting promising prospects for clinical diagnosis. In the future, the excellent catalytic and R_ct performance of the WS₂-PBA will enable its use in biomedical applications.

Keywords: Lactate; One-pot synthesis; Paper-based electrochemical sensor; Prussian blue analogues; Sweat sensor.