Detection of aquaporin-4 antibody using aquaporin-4 extracellular loop-based carbon nanotube biosensor for the diagnosis of neuromyelitis optica

Biosens Bioelectron. 2016 Apr 15:78:87-91. doi: 10.1016/j.bios.2015.11.029. Epub 2015 Nov 12.

Abstract

Here we propose a carbon nanotube (CNT) field-effect transistor (FET) functionalized with aquaporin-4 (AQP4) extracellular loop peptides for the rapid detection of AQP4 antibody without pretreatment. Neuromyelitis optica (NMO) is a rare disease of the central nerve system that affects the optic nerves and the spinal cord. NMO-IgG, a serum antibody in patients, is highly specific for NMO and targets AQP4. We synthesized AQP4 extracellular loop peptides, known as primary autoimmune target in NMO, and immobilized them onto CNT-FET. The sensor showed p-type FET characteristics after the functionalization of peptides. The sensor was able to detect antibody with a detection limit of 1 ng l(-1). Moreover, AQP4 antibody in human serum was detected without any pretreatment. These results indicate that the biosensor can be used for rapid and simple detection of NMO antibody.

Keywords: Aquaporin-4; Carbon nanotube; Field-effect transistor; Neuromyelitis optica.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / immunology
  • Antibodies / isolation & purification*
  • Aquaporin 4 / immunology
  • Aquaporin 4 / isolation & purification*
  • Biosensing Techniques / methods*
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Nanotubes, Carbon / chemistry
  • Neuromyelitis Optica / blood*
  • Neuromyelitis Optica / immunology

Substances

  • Antibodies
  • Aquaporin 4
  • Immunoglobulin G
  • Nanotubes, Carbon