Determination of aflatoxin M1 in milk samples by means of an inductively coupled plasma mass spectrometry-based immunoassay

Abstract

An inductively coupled plasma mass spectrometry (ICP-MS)-based immunoassay has been developed to quantify aflatoxin M1 (AFM1) at ultra-trace levels in milk samples. AFM1 detection is carried out by means of a competitive immunoassay using secondary biotinylated antibodies and streptavidin-conjugated Au nanoparticles. After acid addition, nanoparticles are decomposed and Au signal is registered by means of ICP-MS. Results demonstrate that, under optimum conditions, the limit of detection of the immunoassay (0.005μgkg) is low enough to quantify AFM1 according to current international policies (including the more restrictive European one). Method accuracy and precision was checked by analyzing an AFM1 certified reference material and different milk samples spiked with known amounts of AFM1. AFM1 recovery values range from 80% to 102% whereas inter-assay and intra-assay precision are lower than 15%. Finally, this immunoassay methodology affords a higher dynamic working range (0.012-2.5μgkg) than other immunoassay methodologies described in the literature.

Lanthanide polymer labels for multiplexed determination of biomarkers in human serum samples by means of size exclusion chromatography-inductively coupled plasma mass spectrometry

“…sandwich-based, Western blot, etc.). Antibodies are usually labelled by either metal nanoparticles [5,6] or lanthanides [7,8]. The advantage of elemental nanoparticles is the possibility of the introduction of a significant number of atoms per conjugate which allows the amplification of the analytical response.…”

Occurence of aflatoxin M1 in Northern Africa: A short review

“…Analytical techniques in use for detection of AFM1 in milk and milk products include : Chromatographic techniques (Rice and Ross, 1994 ;Reiter et al, 2009 ;Orata, 2012 ;Laura et al, 2016 ;Shephard, 2016), immunochemical methods (Jiang et al, 2013 ;Vdovenko et al, 2014 ;Yao et al, 2015 ;Kos et al, 2016), rapid methods (Zheng et al, 2006 ;Maragos and Busman, 2010),other research methods have potential utility for the analysis of mycotoxins. They include : infrared spectroscopy (De Girolamo et al, 2009 ;Pérez et al, 2017 ;Sieger et al, 2017), capillary electrophoresis (Maragos and Appell, 2007 ;Shephard, 2008), electronic nose (Olsson et al, 2002 ;Campagnoli et al, 2009), biosensors (Bram Among chromatographic techniques, HPLC is considered the reference method for AFM1 analysis (Beltran et al, 2011;Diniz Andrade et al, 2013).…”

Immunoassays based on inductively coupled plasma mass spectrometry detection: So far so good, so what?

“…A large variety of NPs have been proposed (AgNPs [52][53][54][55], PtNPs [53,56], PbSNPs [57], metal/dye-doped silica NPs [58], Cs-doped magnetic NPs [58,59], UCNPs [30,31], EuPO 4 /LuPO 4 NPs [32], Quantum Dots (QDs) [60][61][62][63][64][65], etc.) but AuNPs [34,[53][54][55]63,[66][67][68][69][70][71][72][73][74][75][76] are usually preferred due to their lower cost and greater commercial availability. When compared to REE-based chelates, the use of inorganic NPs affords some attractive and unique features.…”

“…In general, NPs have been mainly employed for single analyte determinations [31,54,56,57,59,60,62,[64][65][66][67][69][70][71][74][75][76]. Unlike REEbased chelates, and despite the vast number of described NPs proposed in the literature for immunoassays, the use of NPs for multiplexed applications has been scarcely exploited [32,53,55,58,63].…”

“…in human serum samples and cells (Table 2). Nevertheless, they have also been employed for studying manganesedependent protein dynamics of photosystem II in barley [39] and AFM1 levels in milk [54,67]. As regards the analysis of solid samples (Table 3), because traditional workflows for solid-phase immunoassays (e.g.…”