Detecting Lyme Disease Using Antibody-Functionalized Single-Walled Carbon Nanotube Transistors

摘要

We examined the potential of antibody-functionalized single-walled carbonnanotube (SWNT) field-effect transistors (FETs) for use as a fast and accuratesensor for a Lyme disease antigen. Biosensors were fabricated on oxidizedsilicon wafers using chemical vapor deposition grown carbon nanotubes that werefunctionalized using diazonium salts. Attachment of Borrelia burgdorferi (Lyme)flagellar antibodies to the nanotubes was verified by Atomic Force Microscopyand electronic measurements. A reproducible shift in the turn-off voltage ofthe semiconducting SWNT FETs was seen upon incubation with Borrelia burgdorferiflagellar antigen, indicative of the nanotube FET being locally gated by theresidues of flagellar protein bound to the antibody. This sensor effectivelydetected antigen in buffer at concentrations as low as 1 ng/ml, and theresponse varied strongly over a concentration range coinciding with levels ofclinical interest. Generalizable binding chemistry gives this biosensingplatform the potential to be expanded to monitor other relevant antigens,enabling a multiple vector sensor for Lyme disease. The speed and sensitivityof this biosensor make it an ideal candidate for development as a medicaldiagnostic test.