Electrochemical sensor for indirect detection of bacterial population

A homemade ultra-microelectrodes array based on reticulated vitreous carbon (RVC) has been used to monitor the bacterial load (Staphylococcus aureus) coupling electrochemical and chemometric methods. Normal pulse voltammograms (NPV), recorded in filtered solutions, where different amounts of S. aureus had been inoculated, have been analyzed with partial least squares (PLS) regression. Useful signals at selected potentials, chosen with iterative prediction weighting method, were fitted by PLS. The method permits to model the bacterial concentration with respect to the electrochemical current response. The technique seems to work well down to 1 or 2 cells/ml (most probable number method estimation) of inoculated bacteria.