Synergetic effect of Prussian blue film with gold nanoparticle graphite-wax composite electrode for the enzyme-free ultrasensitive hydrogen peroxide sensor

Enzyme-free amperometric ultrasensitive determination of hydrogen peroxide (H2O2) was investigated using a Prussian blue (PB) film-modified gold nanoparticles (AuNPs) graphite-wax composite electrode. A stable PB film was obtained on graphite surface through 2-aminoethanethiol (AET)-capped AuNPs by a simple approach. Field emission scanning electron microscope studies results in formation of PB nanoparticle in the size range of 60-80 nm. Surface modification of PB film on AET-AuNPs-GW composite electrode was confirmed by Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy studies. Highly sensitive determination of H2O2 at a peak potential of -0.10 V (vs. SCE) in 0.1 M KCl PBS, pH = 7.0) at a scan rate of 20 mVs(-1) with a sensitivity of 23.58 mu A/mM was observed with the modified electrode using cyclic voltammetry. The synergetic effect of PB film with AuNPs has resulted in a linear range of 0.05 to 7,800 mu M with a detection limit of 0.015 mu M for H2O2 detection with the present electrode. Chronoamperometric studies recorded for the successive additions of H2O2 with the modified electrode showed an excellent linearity (R (2) = 0.9932) in the range of 4.8 x 10(-8) to 7.4 x 10(-8) M with a limit of detection of 1.4 x 10(-8) M. Selective determination of H2O2 in presence of various interferents was successfully demonstrated. Human urine samples and stain remover solutions were also investigated for H2O2 content.