Sensitive chemiluminescence detection platform for H2O2 and glucose through facile inorganic salt etching of cobalt Prussian blue analogues.

A facile method is reported for rapid etching of cobalt Prussian blue analogues (Co PBA) with inorganic salt NaClO at room temperature, resulting in Co PBA_NaClO, which has been successfully applied to sensitive chemiluminescence (CL) detection. Initially, Co PBA was synthesized using the classical coprecipitation method. Subsequently, without the need for additional steps, Co PBA_NaClO was obtained by simply mixing NaClO with Co PBA at room temperature. This fabrication process led to the formation of numerous Co nanoparticles on the surface of Co PBA, thereby exposing more active sites. Based on the exceptional peroxidase-mimicking activity exhibited by Co PBA_NaClO, we constructed the Co PBA_NaClO-luminol-H₂O₂ CL platform and successfully utilized it for the sensitive detection of both H₂O₂ and glucose, with detection ranges of 0.05-20 µM and 1-50 µM, respectively, and detection limits of 23 nM and 36 nM, respectively. Finally, the possible mechanism of the Co PBA_NaClO-luminol-H₂O₂ system was investigated. This work demonstrates the feasibility of etching PBAs with inorganic salts to enhance their peroxidase-like activity and expands the application of etched PBAs in the area of CL sensing.