Carbon black assisted tailoring of Prussian Blue nanoparticles to tune sensitivity and detection limit towards H2O2 by using screen-printed electrode

The development and characterization of screen-printed electrodes (SPEs) modified with nanocomposites formed by Prussian Blue nanoparticles (PBNPs) and carbon black (CB) for hydrogen peroxide detection are reported. SPEs were modified with PBNPs in several ways: i) by in situ PBNPs chemical deposition on SPEs previously modified with CB dispersion (bilayer), ii) by in situ PBNPs chemical deposition on SPEs prepared with graphite-ink containing CB, and iii) by casting SPEs with a CB/PBNPs dispersion. The use of chemical deposition on SPEs modified with CB in different manners allowed obtaining diverse dimensions of PBNPs, reflected in different analytical properties. The SPEs prepared with CB/PBNPs dispersion, characterized by PBNPs with an average diameter of 19 ± 3 nm, gave the best analytical performance in terms of detection limit (0.3 μM), while the SPEs modified with a bilayer of CB and PBNPs, characterized by PBNPs with an average diameter of 138 ± 15 nm, showed higher sensitivity but higher detection limit. We demonstrated that in using different substrates (graphite ink, graphite ink modified with 10% (w/w) with CB, bilayer graphite ink/CB, CB dispersion) we are able i) to produce CB-SPEs tailored with different sized PBNPs and ii) to tune the analytical performances towards hydrogen peroxide.