Detection of Pyocyanin with a Boron‐doped Diamond Electrode Using Flow Injection Analysis with Amperometric Detection and Square Wave Voltammetry.

We report on the analytical performance of boron‐doped diamond thin‐film electrodes for the detection of the virulence factor, pyocyanin (PYO). The results reported herein confirm the utility of diamond electrodes for the sensitive and reproducible detection of pyocyanin in a 0.1 mol L−1 phosphate buffer (pH 7.4) when using amperometric detection coupled with flow injection analysis (FIA) or square wave voltammetry (SWV). Pyocyanin was reductively detected by hydrodynamic voltammetry in FIA at an E1/2 of −0.31 V vs. Ag/AgCl (3 mol L−1 KCl). The detection figures of merit were a linear dynamic range from 100 to 0.08 μmol L−1, a response reproducibility of 1.3 % (RSD), and a limit of detection of 0.09 μmol L−1 (S/N=3). A comparable linear dynamic range, response reproducibility and limit of detection were observed in preliminary square wave voltammetry measurements. Importantly, these detection figures of merit were obtained using boron‐doped diamond electrodes that received no conventional pretreatment. Some comparison data are presented for nitrogen‐incorporated tetrahedral amorphous carbon (ta‐C : N) and glassy carbon (GC) electrodes. [ABSTRACT FROM AUTHOR]