Abstract

The analytical performances of a novel DNA-ligand system using the time-resolved fluorescence (TRF) response of ochratoxin A (OTA)-terbium-DNA aptamer interaction were tested for the quantitative determination of OTA in wheat. Wheat was extracted with acetonitrile/water (60:40, v/v) followed by clean-up through affinity columns containing a DNA-aptamer-based oligosorbent. Then, OTA was detected by TRF spectroscopy after reaction with a terbium fluorescent solution containing the DNA-aptamer probe. The entire procedure was performed in less than 30 min, including sample preparation, and allowed analysis of several samples simultaneously with a 96-well microplate reader. The average recovery from samples spiked with 2.5-25 ?g kg(-1) OTA was 77%, with a relative standard deviation lower than 6% and a quantification limit of 0.5 ?g kg(-1). Comparative analyses of 29 naturally contaminated (up to 14 ?g kg(-1)) wheat samples using the aptamer-affinity column/TRF method or the immunoaffinity column/high-performance liquid chromatography method showed good correlation (r = 0.985) in the range tested. The trueness of the aptamer-based method was additionally assessed by analysis of two quality control wheat materials for OTA. The DNA-ligand system is innovative, simple and rapid, and can be used to screen large quantities of samples for OTA contamination at levels below the EU regulatory limit with analytical performances satisfying EU criteria for method acceptability.

Autore Pugliese

• De Girolamo Annalisa , Schena Roberto

Tutti gli autori

• De Girolamo A.; Le L.; Penner G.; Schena R.; Visconti A.

Titolo volume/Rivista

Analytical & bioanalytical chemistry

Anno di pubblicazione

2012

ISSN

1618-2642

ISBN

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Numero di citazioni Wos

Nessuna citazione

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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