In-situ Electrochemical Synthesis Of Prussian Blue Composite With Gold Nanoparticles And Its Application In Hydrogen Peroxide Biosensor

This manuscript presents in-situ electrochemical synthesis of Prussian Blue-gold nanoparticles (PB- AuNPs) composite for application in hydrogen peroxide (H2O2) biosensor. The SEM image clearly showed the presence of AuNPs of size in range of 50 to 200 nm spread on PB matrix. UV-Visible spectra showed absorbance peak at 530 nm corresponding to AuNPs and a hump in 690-740 nm region for PB, confirming the synthesis of composite. The cyclic voltammetry (CV) showed the surface coverage of 3.65 x 10 -9 mol/cm 2 for pure PB film and 4.33 x 10 -9 mol/cm 2 for PB-AuNPs film, with diffusion coefficient of 1.19 x 10 -9 cm 2 /s, and 5.64 x 10 -9 cm 2 /s respectively. The film thickness is found to be 2.4 x 10 -12 cm for PB and 2.9 x 10 -12 cm for PB-AuNPs composite. The concentration of redox active centers (Fe +3/+2 ) is 3.5 moles/cm 3 for ITO/PB and 4.1 moles/cm 3 for ITO/PB-AuNPs respectively. The CV of ITO/PB showed one redox couple at 0.118 V and 0.215 V, whereas with ITO/PB-AuNPs electrode,