Antibody-based protein detection using piezoresistive cantilever arrays

A piezoresistive cantilever array platform with electrical read-out was applied for protein detection using GST (glutathione-S-transferase) and GST antibodies as a model system. Sensing was performed in the static deflection mode under constant flow conditions. The GST antibodies were directly immobilized on the cantilever gold surface by means of free thiol groups. The setup allowed simultaneous deflection measurements with sensor and control-antibody-immobilized reference cantilevers and enabled detection of 1 ng μl-1 (40 nM) of GST protein, which is similar to the sensitivity reported for cantilever sensors using an optical read-out system