Electrochemical behavior of zanamivir at gold-modified boron-doped diamond electrodes for an application in neuraminidase sensing

This study emphasizes the electrochemical detection of Neuraminidase (NA) based on NA inhibition by Zanamivir. The detection method was developed based on the difference of electrochemical responses of Zanamivir in the presence and the absence of NA in phosphate buffer solution (pH 5.5). Gold and gold-modified boron-doped diamond was used as the working electrode and the measurement was conducted using cyclic voltammetry method. A linear calibration curve of Zanamivir was observed in the concentration range of 5 × 10^-6-1 × 10^-4 mol/L (R² = 0.991), with the estimated limit of detection (LOD) of 1.49 × 10^-6 mol/L. The presence of NA increases the peak current of gold oxidation and reduction with linear calibration curves were monitored in the concentration range of 0-15mU (R² = 0.996). An estimated LOD of 0.25mU NA and an excellent reproducibility of the detection with an RSD of 1.18% can be achieved. Application of a real sample was successfully demonstrated for NA detection in the presence of mucin, suggested that the method is promising for pharmaceutical or medical application.