Label free electrochemical aptasensor for ultrasensitive detection of ractopamine

Biosens Bioelectron. 2016 Mar 15;77:347-52. doi: 10.1016/j.bios.2015.09.050. Epub 2015 Sep 26.

Abstract

A label free electrochemical (EC) aptasensor for ultrasensitive detection of ractopamine (RAC) was developed. A special immobilization media consisting of gold nanoparticles/poly dimethyl diallyl ammonium chloride-graphene composite (AuNPs/PDDA-GN) was utilized to improve conductivity and performance of the biosensor. The RAC aptamer was attached on AuNPs of the composite membrane via Au-S bond. The fabrication process of the EC aptasensor was characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The peak currents obtained by differential pulse voltammetry decreased linearly with the increasing of RAC concentrations and the sensor responds approximately logarithmically over a wide dynamic range of RAC concentration from 1.0 × 10(-12)mol/L to 1.0 × 10(-8)mol/L. The linear correlation coefficient of the developed aptasensor was 0.998, the limit of detection was 5.0 × 10(-13)mol/L. The proposed EC aptasensor displayed good stability, reproducibility and robust operation in animal urine. Particularly, the generality of the fabrication approach of electrochemical aptasensor is highlighted with a further example for illegal drugs detection via the aptamer identification.

Keywords: Aptamer; Cyclic voltammetry; Differential pulse voltammetry; Gold nanoparticles; Graphene; Ractopamine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aptamers, Nucleotide / chemistry*
  • Biosensing Techniques / instrumentation*
  • Conductometry / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Gold / chemistry*
  • Growth Substances / urine
  • Metal Nanoparticles / chemistry*
  • Phenethylamines / urine*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Staining and Labeling

Substances

  • Aptamers, Nucleotide
  • Growth Substances
  • Phenethylamines
  • ractopamine
  • Gold