Ultra-sensitive biosensor based on genetically engineered acetylcholinesterase immobilized in poly (vinyl alcohol)/Fe-Ni alloy nanocomposite for phosmet detection in olive oil

Food Chem. 2016 Jul 15:203:73-78. doi: 10.1016/j.foodchem.2016.02.014. Epub 2016 Feb 2.

Abstract

An ultra-sensitive screen-printed biosensor was successfully developed for phosmet detection in olive oil, based on a genetically-engineered acetylcholinesterase (AChE) immobilized in a azide-unit water-pendant polyvinyl alcohol (PVA-AWP)/Fe-Ni alloy nanocomposite. Fe-Ni not only allowed amplifying the response current but also lowering the applied potential from 80 mV to 30 mV vs Ag/AgCl. The biosensor showed a very good analytical performance for phosmet detection, with a detection limit of 0.1 nM. This detection limit is lower than the allowable concentrations set by international regulations. In addition to the good reproducibility, operational and storage stability, the developed biosensor was successfully used for the determination of phosmet in olive oil samples without any laborious pre-treatment. The phosmet recovery rate was about 96% after a simple liquid-liquid extraction.

Keywords: Acetylcholinesterase; Biosensor; Nanocomposite; Olive oil; Organophosphorus pesticides; Screen-printed electrodes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / chemistry*
  • Acetylcholinesterase / genetics
  • Alloys / chemistry
  • Biosensing Techniques / methods*
  • Enzymes, Immobilized / chemistry*
  • Enzymes, Immobilized / genetics
  • Iron / chemistry*
  • Limit of Detection
  • Liquid-Liquid Extraction
  • Nanocomposites / chemistry*
  • Nickel / chemistry*
  • Olive Oil / analysis*
  • Phosmet / analysis*
  • Polyvinyl Alcohol / chemistry*
  • Reproducibility of Results

Substances

  • Alloys
  • Enzymes, Immobilized
  • Olive Oil
  • ferronickel
  • Nickel
  • Polyvinyl Alcohol
  • Iron
  • Acetylcholinesterase
  • Phosmet