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 external magnetic field into a dense electrically conducting sensor strip that measures the decrease in current when a sample containing c-Myc Ag is deposited on it. Prototypes are rapidly fabricated materials that cost less than 20 cents (Canadian) for each sensor. With larger current decreases due to real-time specific Ag-Ab binding for higher c-Myc concentrations, the biosensor distinguishes between picomolar c-Myc concentrations within a minute, offering proof of concept of a simple, rapid, economical, and sensitive method to detect specific molecules recognizable by Abs.
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Abdel Rahman Abdel
AR
Fattah
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Ahmed M
AM
Abdalla
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Sarah
S
Mishriki
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Elvira
E
Meleca
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Fei
F
Geng
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Suvojit
S
Ghosh
Department of Mechanical Engineering, ‡Department of Engineering Physics, §School of Biomedical Engineering, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Ishwar K
http://orcid.org/0000-0002-8713-4188
IK
Puri
D000906:Antibodies; D015374:Biosensing Techniques; D002170:Canada; D037742:Nanotubes, Carbon; D011327:Printing
D000906:Antibodies; D037742:Nanotubes, Carbon
antigens; bioinks; biosensors; magnetic carbon nanotubes; self-assembly