The electrochemical detection of staphylococcus aureus bacteria by the amoxicillin modified natural phosphate (AMX-Np) is decried. The AMX-NP electrodes were used for the detection of low optical densities of staphylococcus aureus by using the cyclic voltammetry (cv) and the square waves voltammetry (swv). Some electrochemical properties, in particular the influence of the pH, the optical density of the bacterium were studied. The elaborate electrode was the subject then of an analytical application for purposes of the detection of staphylococcus aureus in the potato juice.