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

TL;DR

This paper presents a novel antibody-functionalized single-walled carbon nanotube transistor biosensor capable of rapidly and accurately detecting Lyme disease antigens at very low concentrations, with potential for clinical diagnostic applications.

Contribution

The study introduces a new SWNT FET biosensor functionalized with Lyme disease antibodies, demonstrating high sensitivity and specificity for antigen detection.

Findings

Detects Lyme antigen at 1 ng/ml in buffer

Shows strong response over clinically relevant concentration range

Potential for multiplexed Lyme disease diagnostics

Abstract

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