Electrochemical behavior of nanosized Prussian blue self-assembled on Au electrode surface

Prussian blue (PB) particles with the size of ca. 50 nm were immobilized onto a gold electrode using cysteine as a bridge between the gold surface and the nanoparticles by the self-assembled method. The PB modified electrode exhibited two couples of voltammetric peaks with E-A(0') = 0.210 V and E-B(0') = 0.236 V (E-0' = (E-a(0') + E-c(0'))/2) vs SCE in 1.0 M KCl electrolyte at the scan rate of 5.0 mV s(-1). The number of particles adsorbed on the electrode surface is 4.54 x 10(10) per cm(2) (equivalent to 1.00 x 10(-8) mol cm(-2)) according to the integrated Faraday charge. The X-ray diffraction (XRD) studies on the PB particles showed that the Bragg peaks widened owing to the small size effect of the particles, and the transmission electron microscopy (TEM) confirmed that the particles are nanosized particles. The electrochemical behavior was explained by the difference of nature between the surface atoms and the inner atoms. (C) 2002 Elsevier Science B.V. All rights reserved.