Irreversible chemical AFM-based fishing for detection of low-copied proteins

Abstract

The atomic-force microscopy-based method of irreversible chemical AFM-fishing (AFM-IFchem) has been developed for the detection of proteins existing at ultra-low concentrations in solution. Using this method, a very low concentration of horseradish peroxidase (HRP) protein (10−17 M) was detected in solution. A theoretical model that allows the description of obtained experimental data has been proposed. This model takes into consideration both transport of the protein from the bulk solution onto the AFM-chip sur-face and its irreversible binding to the activated area.