Development of an impedimetric aflatoxin M1 biosensor based on a DNA probe and gold nanoparticles

Biosens Bioelectron. 2011 May 15;26(9):3806-11. doi: 10.1016/j.bios.2011.02.038. Epub 2011 Mar 1.

Abstract

The present work describes the construction and application of a new DNA biosensor for detection of aflatoxin M1. In order to immobilize a thiol-modified single stranded DNA (ss-HSDNA) probe that specifically bound aflatoxin M1, a self-assembled monolayer of cysteamine and gold nanoparticles on the SAM were prepared on gold electrodes, layer-by-layer. The assembly processes of cysteamine, gold nanoparticles, and ss-HSDNA were monitored with the help of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. K3[Fe(CN)6]/K4[Fe(CN)6] solution was used as a redox probe for electrochemical measurements. The biosensor provided a linear response to aflatoxin M1 over the concentration range of 1-14 ng/mL with a standard deviation of ±0.36 ng/mL. Finally, the biosensor was applied to a series of real milk samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aflatoxin M1 / chemistry
  • Aflatoxin M1 / isolation & purification*
  • Biosensing Techniques*
  • DNA / chemistry*
  • Dielectric Spectroscopy
  • Electric Impedance
  • Gold / chemistry
  • Nanoparticles / chemistry

Substances

  • Aflatoxin M1
  • Gold
  • DNA