Electrochemical detection of hepatitis C viral NS3-4A protease

Here we lay the ground work for the detection of hepatitis C viral NS3-4A protease exploiting peptide-protein interaction. The NS3-4A protease is inhibited by N-terminal cleavage products. Our approach is based on the formation of a self-assembled monolayer (SAM) of a ferrocene amino acid derivative on an electrode surface. A short NS3-4A specific inhibitory peptide (Asp-Glu-Ile-Val-Pro-Nva) was then covalently attached to the electrode surface. The interaction of the peptide, through the C-terminal, with the protein was quantified using electrochemical techniques. The systems exhibit a linear relationship between the measured signal and NS3-4A concentration in the range of 10-100 pM with a detection limit of 5 pM.