Layer-by-layer self-assembly aluminum Keggin ions/Prussian blue nanoparticles ultrathin films towards multifunctional sensing applications

In this study we described the nanocomposites films of specially synthesized inorganic Prussian blue (PB) nanoparticles and polyoxocation Al13 Keggin ions that possess the excellent sensing activities. Film fabrication using layer-by-layer (LBL) self-assembly technique was followed by electrochemical characterization. The assembled multilayer Al13/PB films as sensor devices for both the catalytic reduction of H2O2 and detecting the change of relative humidity were also investigated. The sensitivity of the biosensor was 0.886 mA cm−2 mM−1, and about two orders of magnitude change in resistance was observed as the relative humidity increasing from 5 to 95%. Both sensors exhibited good reproducibility, wide linear range. The performance and multifunctional abilities of these nanocomposites promise potential applications in biosensors, environmental controlling system and biomedical devices.