Sensitivity enhancement for mycotoxin determination by optical waveguide lightmode spectroscopy using gold nanoparticles of different size and origin

Food Chem. 2018 Nov 30;267:10-14. doi: 10.1016/j.foodchem.2018.04.089. Epub 2018 Apr 23.

Abstract

Mycotoxins, present in a wide range of food and feed commodities, are toxic secondary metabolites produced by a number of different fungi. Certain mycotoxins do not readily degrade at high temperatures, therefore are resistant to food processing, and consequently are present in the human and animal food supply. Optical waveguide lightmode spectroscopy (OWLS) was applied for the detection of aflatoxin B1, in a competitive immunoassay format, to compare the analytical sensitivity achieved with an immunosensor design allowing signal enhancement by increasing the sensor surface through immobilization of gold nanoparticles (AuNPs) of different size and origin (obtained by chemical or biotechnological synthesis). The effects of AuNPs median size, the methods of sensitization and the biochemical parameters on immunosensor performace were examined. After optimization of the sensitized sensor surface, an immunosensing method was developed for the analysis of aflatoxin in paprika matrix and the results were compared with HPLC reference measurements.

Keywords: 11-Mercaptoundecanoic acid (PubChem CID: 543502); Aflatoxin B1; Aflatoxin B1 (PubChem CID: 186907); AuNP (PubChem CID: 23985); BioAuNPs; Dichloromethane (PubChem CID: 6344); Ethanolamine hydrochloride (PubChem CID: 74819); Immunosensor; N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (PubChem CID: 15908); N-hydroxysuccinimide (PubChem CID: 80170); OWLS; Spice paprika; Tetrachloroauric acid trihydrate (PubChem CID: 44134746); Tetramethylammonium hydroxide (PubChem CID: 44134746); γ-Aminopropyltriethoxysilane (PubChem CID: 13521).

MeSH terms

  • Aflatoxin B1 / analysis
  • Capsicum / metabolism
  • Chromatography, High Pressure Liquid
  • Food Contamination / analysis
  • Gold / chemistry*
  • Hydrogen-Ion Concentration
  • Lasers, Gas
  • Metal Nanoparticles / chemistry*
  • Mycotoxins / analysis*
  • Particle Size
  • Refractometry / methods*
  • Serum Albumin, Bovine / chemistry

Substances

  • Mycotoxins
  • Serum Albumin, Bovine
  • Gold
  • Aflatoxin B1