*3.5.4 Reproducibility*

For Ag-VD2 concentration, the BSA/Ab-VD2/CD-CH/ITO bioelectrode demonstrated high repeatability. Five distinct bioelectrodes each recorded responses to Ag-VD2 at a constant concentration of 30 ng mL−1. The highest current value showed no discernible change. It was determined that the standard deviation was 0.3. The low RSD value (0.19%) and high repeatability properties of the BSA/Ab-VD2/CD-CH/ ITO were further evidence. After five usages, there was a little decline [69, 70].
