Immunosensor for diagnosis of Alzheimer disease using amyloid-β 1-40 peptide and silk fibroin thin films

Mater Sci Eng C Mater Biol Appl. 2016 Nov 1:68:338-342. doi: 10.1016/j.msec.2016.05.101. Epub 2016 May 24.

Abstract

Layer-by-Layer (LbL) films containing silk fibroin (SF) and the 40 aminoacid-long amyloid-β peptide (Aβ1-40) were prepared with the purpose of developing a new prototype of an electrochemical immunosensor. The film showed a satisfactory growth in quartz substrate and screen-printed carbon electrodes, as observed by UV-vis spectroscopy and cyclic voltammetric, respectively. The peptide immobilized in LbL films in junction with SF shows secondary structure induced, as shown by circular dichroism measurements, favoring the interaction SF/peptide LbL film with the specific antibody. Immunosensor showed a linear response in the presence of the antibody with concentrations from 0 to 10ngmL(-1) both analyzed by current changes in 0.3V and voltammogram area. This system can be applied as a new prototype for preliminary diagnosis of Alzheimer's disease.

Keywords: Alzheimer's disease; Amyloid-β peptide; Immunosensor; Layer-by-layer; Silk fibroin.

MeSH terms

  • Alzheimer Disease* / diagnosis
  • Alzheimer Disease* / metabolism
  • Amyloid beta-Peptides / metabolism*
  • Animals
  • Antibodies / chemistry*
  • Biosensing Techniques / methods*
  • Fibroins / chemistry*
  • Humans
  • Membranes, Artificial*
  • Peptide Fragments / metabolism*

Substances

  • Amyloid beta-Peptides
  • Antibodies
  • Membranes, Artificial
  • Peptide Fragments
  • amyloid beta-protein (1-42)
  • Fibroins