Chromium(III) hexacyanoferrate(II)-based chemical sensor for the cathodic determination of hydrogen peroxide

A cathodic scheme to measure hydrogen peroxide by utilizing a membrane free chromium(III) hexacyanoferrate(II) based chemical sensor is described. The cluster is prepared simply by generating a chromium(III) hexacyanoferrate(II) cluster electrochemically on a rotating disk glassy carbon electrode. Subsequently, the hydrogen peroxide can be measured at 0 V versus Ag/AgCl. This approach significantly reduces interferences, especially those by easy oxidizable compounds such as catechol and ascorbic acid. Also, no significant oxygen interference is observed at this working potential, Several electrolytes mere carefully investigated. The calibration curve was linear up to 1.3 mM (r = 0.9992) with a typical response of the sensor of about 5.6 s with injection of 0.05 mM hydrogen peroxide. The detection limit of this chemical sensor is 3.0 X 10(-8) M (S/N = 3) with a low-pass filter (time constant 0.1 s), The sensitivity of the sensor is 11.52 X 10(-6) A l mmol(-1) mm(-2) (r = 0.9992). The RSD of this sensor is 1.1%.