A Boron Doped Diamond Electrode Modified with Nano-carbon Black for the Sensitive Electrochemical Determination of Chlorogenic Acid

An electrochemical method was developed for the sensitive determination of chlorogenic acid using a boron doped diamond electrode (BDDE) modified with nano-carbon black (nano-CB). The active surface areas were found to be 0.059 and 0.146 cm(2) for the unmodified BDDE, and nano-CB/BDDE, respectively. Compared with a BDDE, the nano-CB/BDDE exhibited a well-defined redox couple for chlorogenic acid. In addition, the plot of the peak current response changing from a square root to a linear dependence on scan rate is attributed to the transition from planar diffusion to surface behaviour. The anodic and cathodic peak separations (Delta E-p) were 97 mV and 14 mV at BDDE and nano-CB/BDDE, respectively. The decrease in Delta E-p at the proposed electrode indicated that the process of chlorogenic acid was greatly accelerated. Square wave voltammetry (SWV) exhibited a dynamic range in which the current versus the concentration of chlorogenic acid were linear from 2.0x10(-8) to 2.0x10(-6) M with a LOD of 4.1x10(-9) M (based on 3S(b)/m). The nano-CB modified BDDE provided improved electrochemical behavior, high electrocatalytic activity, high sensitivity and good reproducibility.