Single Nannoparticles On Gold (Au) Ultramicroelectrode Lab Analysis

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ABSTRACT Current response of ascorbic acid-stabilized copper (Cu) single nanoparticles (NPs) collision on gold (Au) ultramicroelectrode (UME) surface was observed by the electrocatalytic amplification method. When the applied potential to the UME was 0.4 V, blip (or spike) response of current, which is responsible for the self-oxidation of Cu NP, was obtained. When the applied potential was over 0.5 V, the blip response combined with staircase response was obtained. The blip part indicates the oxidation of Cu NP, and the staircase part indicates the steady-state electrocatalytic reaction by oxidized Cu NPs. Here, the glucose oxidation was used as the electrocatalytic reaction for the observation of single NP collision. The transferred charged …show more content…
Bard group and many other groups. The detection techniques mostly based on amperometric methods exploiting the electrocatalytic difference between the material of NP and ultramicroelectrode (UME) or potentiometric method measuring open circuit potential change upon the NP adsorption. The amperometric methods can be classified mainly into three classes such as electrocatalytic amplification, direct particle electrolysis, and UME …show more content…
Therefore, the detailed mechanism is not presented in this study. However, many previous studies indicate that the CuO or Cu(III) oxide is essential for the catalytic oxidation of carbohydrates. Therefore, Cu oxide has considerable electrocatalytic activity for the glucose oxidation even better than the pristine Cu.
As shown in the Scheme 1, when the Cu NP collides on the inert electrode where the appropriate potential, adaptable for the both the oxidation of Cu and electrocatalytic oxidation of glucose by Cu oxide is applied, the blip plus staircase current response is available by the self-oxidation of Cu NP and electrocatalytic reaction by oxidized Cu NP, respectively. To achieve this, the choice of inert electrode and appropriate potential is important, and Au UME was suitable for this.
For the comparison of glucose oxidation ability between Cu and Au and the determinant, the appropriate potential for the successive observation of combined signal of Cu NP collision, not only electro-oxidation of Cu and Au but also glucose oxidation ability between Cu and Au were investigated by cyclic voltammetry

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