A sensitive electrochemical protein quantification method

This article presents a sensitive electrochemical method for the quantifica tion of proteins. The assay used the biuret reaction, which is based on the complexation of proteins with copper ions to form a copper-protein complex . In the present approach, once copper ions were complexed with the protein , they were released by an acidic treatment and simultaneously separated by ultracentrifugation from the protein sample. This allowed differential pul se anodic stripping voltammetry (DPASV) of Cu2+ on carbon rotogravure print ed electrodes (CARPEs). A nM detection limit for bovine serum albumin (BSA) was found with this method. The kinetics of this assay were tested and it resulted that the total assay can be carried out in 27 min, including incub ation, washing steps and detection.