Using antibody coated gold nanoparticles as fluorescence quenchers for simultaneous determination of aflatoxins (B1, B2) by soft modeling method

• Gold-labeled antibodies can quench the fluorescence of the aflatoxins owing to FRET.
• The fluorescence spectra of total aflatoxins severely overlap.
• EEM is usually characterized by several quite overlapped spectra.
• MCR-ALS can be applied to EEMs to simultaneous determination of AFB1 and AFB2.

Preparation of antibody coated gold nanoparticles (GNPs) specific to aflatoxins B1 and B2 and its use in rapid aflatoxin determination method was presented in this paper. The formation of gold-labeled antibodies was accomplished at optimal condition. The processes were monitored by UV–visible light measurements, transmission electron microscopy (TEM) and fluorescence spectroscopy. It was found that GNPs with definite surface plasmon absorption can quench the fluorescence of aflatoxins. The quenching of the fluorescence of excitation emission matrices (EEMs) of both aflatoxin samples, provoked by gold-labeled antibodies, was studied by multivariate curve resolution with alternating least squares (MCR–ALS) method. Quantitative results obtained from aflatoxins in pistachio nut samples by MCR–ALS are compared to those obtained using the HPLC method. There are no significant differences between the methodology proposed and the standard one, and may be a good alternative to the traditional methods of analysis for aflatoxins.