Magnetic Printing of a Biosensor: Inexpensive Rapid Sensing To Detect Picomolar Amounts of Antigen with Antibody-Functionalized Carbon Nanotubes

When an antibody (Ab) is immobilized on its surface, a carbon nanotube (CNT) becomes a biosensor that detects the corresponding antigen (Ag) because Ag-Ab complexes formed on the CNT surface moderate the current flow through it. We synthesized a biological ink containing CNTs that are twice functionalized, first with magnetic nanoparticles and thereafter with the anti-c-Myc monoclonal Ab. The ink is pipetted and dynamically self-organized by an …