Development of neuraminidase detection using gold nanoparticles boron-doped diamond electrodes

Gold nanoparticles-modified boron-doped diamond (AuNPs-BDD) electrodes, which were prepared with a self-assembly deposition of AuNPs at amine-terminated boron-doped diamond, were examined for voltammetric detection of neuraminidase (NA). The detection method was performed based on the difference of electrochemical responses of zanamivir at gold surface before and after the reaction with NA in phosphate buffer solution (PBS, pH 5.5). A linear calibration curve for zanamivir in 0.1 M PBS in the absence of NA was achieved in the concentration range of 1 × 10^-6 to 1 × 10^-5 M (R² = 0.99) with an estimated limit of detection (LOD) of 2.29 × 10^-6 M. Furthermore, using its reaction with 1.00 × 10^-5 M zanamivir, a linear calibration curve of NA can be obtained in the concentration range of 0-12 mU (R² = 0.99) with an estimated LOD of 0.12 mU. High reproducibility was shown with a relative standard deviation (RSD) of 1.14% (n = 30). These performances could be maintained when the detection was performed in mucin matrix. Comparison performed using gold-modified BDD (Au-BDD) electrodes suggested that the good performance of the detection method is due to the stability of the gold particles position at the BDD surface.