Zearalenone In Cereals Research Articles

Smartphone-assisted ratiometric FRET aptasensor based on quantum dots and gold nanoparticles for point-of-care testing of zearalenone in cereals

Herein, a ratiometric fluorescence aptasensor was established for zearalenone (ZEN) detection based on fluorescence resonance energy transfer (FRET) between aptamer-modified CdTe quantum dots (QDs) as donor and gold nanoparticles (AuNPs) as acceptor. The fluorescence of CdTe QDs quenched by AuNPs based on FRET, while Si QDs with blue fluorescence as reference. The aptamer-modified CdTe QDs were adsorbed to ZEN in the presence of ZEN, and the distance between the energy receptor and the donor increased, which prevented the FRET and led to the fluorescence recovering of CdTe QDs. The aptasensor exhibited a limit of detection of 3.5 pg/mL with a linear range of 0.01–100 ng/mL. In addition, a portable detection device was constructed by integrating with smartphone for point-of-care testing (POCT) of ZEN with satisfactory results, which could provide a promising application for visual POCT of ZEN in cereals.

Pore Size Adjustment Strategy for the Fabrication of Molecularly Imprinted Covalent Organic Framework Nanospheres at Room Temperature for Selective Extraction of Zearalenone in Cereal Samples.

Covalent organic frameworks (COFs) are attractive adsorbents for sample pretreatment due to their unique structure and properties. However, the selectivity of COFs for the extraction of hazardous compounds is still limited due to the lack of specific interactions between COFs and targets. Herein, we report a pore size adjustment strategy for room-temperature synthesis of molecularly imprinted COF (MICOF) for selective extraction of zearalenone (ZEN) in complex food samples. The three-dimensional building block tetra(4-aminophenyl) methane was used as a functional monomer, while dialdehyde monomers with different numbers of benzene ring were used to adjust the pore size of MICOF to match with the size of ZEN molecules. The prepared MICOF gave the largest adsorption capacity of 177.2 mg g-1 and the highest imprinting factor of 10.1 for ZEN so far. MICOF was used as the adsorbent for dispersed solid-phase extraction in combination with high-performance liquid chromatography for the determination of trace ZEN in cereals. The high selectivity of the developed method allows simple aqueous standard calibration for the matrix effect-free determination of ZEN in food samples. The limit of detection and the recoveries of the developed method were 0.21 μg kg-1 and 93.7-101.4%, respectively. The precision for the determination of ZEN was less than 3.8% (RSD, n = 6). The developed method is promising for the selective determination of ZEN in complex matrices.

Colorimetric and photothermal dual-mode immunosensor based on Ti3C2Tx/AuNPs nanocomposite with enhanced peroxidase-like activity for ultrasensitive detection of zearalenone in cereals.

A novel peroxidase-like nanozyme has beenconstructed by decorating two-dimensional Ti3C2Tx nanosheets (Ti3C2Tx NSs) with gold nanoparticles (AuNPs) to develop a colorimetric and photothermal dual-mode immunosensor. TheTi3C2Tx/AuNPs nanocomposite-catalyzed 3,3',5,5'-tetramethylbenzidine (TMB)-H2O2 reaction system produces the one-electron oxidation product of TMB (oxTMB), which exhibits color change and strong near-infrared (NIR) laser-driven photothermal effect at 808nm laser irradiation. Given these characteristics, the developed immunosensor achieves ultrasensitive dual-mode detection of zearalenone (ZEN) by measuring colorimetric and photothermal signals with a microplate reader and a portable infrared thermometer, respectively. Under optimal working conditions, the limit of detection (LOD) of ZEN is 0.15 pg mL-1 for thecolorimetric mode and 0.48 pg mL-1 for thephotothermal mode. Inthe analysis of actual contaminated cereals samples, the test result of this method wasconsistent with that of UPLC-MS/MS. The proposed colorimetric and photothermal dual-mode immunosensor offers a new strategy for the low-cost detection of hazardous substances. Theapplication of awidely used household infrared thermometer makes the signal readout more convenient, which provides great prospects in food safety and environment inspection applications.

A bimetallic organic framework based fluorescent aptamer probe for the detection of zearalenone in cereals

In this work, a bimetallic organic framework (Cu/UiO-66) based “turn on” fluorescent aptamer probe was designed for the high-efficiency detection of zearalenone (ZEN). In the probe, the 6-carboxyfluorescein-labeled aptamer (FAM-Apt) was used as the recognition element, and the electrostatic interaction, coordination effect, and photoinduced electron transfer effect between FAM-Apt and Cu/UiO-66 caused fluorescence quenching. When ZEN existed, FAM-Apt recognized ZEN specifically, causing FAM-Apt to separate from the surface of Cu/UiO-66 and recovery of fluorescence. Under the optimal conditions, the probe had a linear detection range of 0.5 ng/mL–60 ng/mL, and the detection limit was 0.048 ng/mL. The application potential of the probe was verified by real detection of various cereals and their products, with a standard recovery from 83.67 %–106.8 %. The development of this efficient, rapid, and sensitive ZEN detection method provides a new platform for the quality control of cereals and their products.

Rapid detection of zearalenone in cereals using La3+-doped upconversion nanoparticles-based immunochromatographic assay

A novel fluorescent immunochromatographic assay (ICA) with excellent specificity and sensitivity for evaluating trace residues of zearalenone (ZEN) in cereal samples was successfully developed. La3+-doped upconversion nanoparticles (UCNPs) were assessed as antibody labels, following optimization of doping ratios. Our results indicated that 20% La3+-doped UCNPs had superior morphological structure and fluorescence characteristics, making them the optimal UCNPs. After labeling 20% La3+-doped UCNPs with ZEN monoclonal antibodies (mAbs), optimal polyacrylic acid amount, coupled mAbs amount, detection time, and fluorescent immunoprobe concentrations were determined as 2.0 mL, 20 μg, 10 min, and 8 mg/mL, respectively. Under optimized detection conditions, the limit of detection (LOD) for ZEN standard solutions was 0.25 ng/mL with coefficients of variation (CVs) ＜ 8.67% and a high linear correlation (R2 = 0.9944). Furthermore, specificity analysis demonstrated that prepared test strips were highly specific for the target mycotoxin. The LODs of ZEN in wheat and maize were both 0.5 μg/kg in spiking recovery experiments, and the recoveries were 87.65%–99.26% and 84.12%–95.12% with the CVs being 1.29%–7.14% and 4.03%–9.01%, respectively, confirming that the optimal UCNPs-ICA was efficient, straightforward, and suitable for rapid on-site screening of ZEN in cereals.

An improved up-conversion nanoparticles-based immunochromatographic assay for rapid detection of zearalenone in cereals

A novel improved up-conversion nanoparticles-based immunochromatographic assay (IUCNPs-ICA) was developed for the detection of zearalenone (ZEN). Lu3+-doped UCNPs were synthesized using the solvothermal method, and the UCNPs doped with 30 % Lu3+ displayed optimal optical properties. The IUCNPs-ICA was subsequently developed for the detection of ZEN in cereals under optimized conditions. The detection time and limit of detection (LOD) were 10 min and 0.1 μg/L, respectively. Moreover, a good linear relationship was observed from 0 to 100 μg/L ZEN (r2 = 0.9946) and high specificity for other mycotoxins. LODs in spiked maize and wheat reached 0.16 μg/kg, and recovery rates were 82.11–100.76 % and 79.64–98.51 %. There was good consistency between the results of IUCNPs-ICA, colloidal gold-ICA, and high-performance liquid chromatography (HPLC) in the detection of natural cereal samples. The collective results support the utility of IUCNPs-ICA as a reliable on-site screening method for ZEN residue analysis in various cereals.

Aptamer-locker probe coupling with truncated aptamer for high-efficiency fluorescence polarization detection of zearalenone

Zearalenone (ZEN) is a kind of mycotoxin with estrogen-like effect. The presence of ZEN in cereals is potentially harmful to the health of humans. Herein, for the first time, the binding mechanism of ZEN aptamer with 19 bases (Z19) were systematically studied by molecular dynamics, circular dichroism and isothermal titration calorimetry. The binding driving forces, key bases of Z19 to ZEN, the conformational changes and thermodynamic information were originally found. On this basis, by employing the inherent rapid nature of fluorescence polarization and target recycling induced by Exo III, a novel fluorescence polarization aptasensor was constructed. The realized “add and measure” detection mode can be completed within one hour. Under the optimal conditions, the detection platform showed excellent analytical performance with a linear range of 0.01–100 ng/mL and a limit of detection as low as 0.004 ng/mL. Moreover, the practicability and reliability of the constructed strategy were confirmed with standard HPLC-MS method in corn and wheat samples. The established aptasensor with enhanced sensitivity broaden the application scope of fluorescence polarization technique, especially in detection targets of low molecular weight.

IN VITRO STUDY OF THE EFFICACY OF MYCOTOXINS DEGRADATION BY FEED ENZYMES

Providing healthy and safe food in terms of mycotoxicological safety is an imperative for not only good and sustainable livestock production, but also for the population that consumes food of both plant and animal origin. Climate change in the temperate regions of southern Europe has led to frequent occurrence of aflatoxins, deoxynivalenol and zearalenone in cereals. In order to reduce harmful effects of these toxins on animal health as well as to avoid large economic losses, various feed additives are increasingly being used. All of them must first of all be safe, and then have certain efficiency in the fight against mycotoxins. Although in vivo experiments are mandatory to assess the efficacy, in vitro test offers the advantage of rapid screening of the efficacy of a large number of food additives. In this paper, the efficiency of two commercial products belonging to the enzyme group for animal nutrition was investigated for degradation of aflatoxin B1, zearalenone and deoxynivalenol using in vitro experiments. For this purpose, two different methodologies were used according to the recommendation of the enzyme manufacturer. The percentage of mycotoxin degradation was recorded by high pressure liquid chromatography and ELISA methods. One of the tested enzymes showed a very high efficiency in zearalenone degradation being as much as 96%. Both tested enzyme samples showed similar percentage of aflatoxin B1 degradation (about 35%). Deoxynivalenol was not significantly degradable under the applied test conditions.

Rainbow latex microspheres lateral flow immunoassay with smartphone-based device for simultaneous detection of three mycotoxins in cereals

The coexistent pollution of multiple mycotoxins displays a synergistic toxicity effect that significantly threatens human health. Therefore, it is essential to establish a rapid detection method for multi-mycotoxins in food. In this study, red, green, and blue latex microspheres (LMs) were applied as the aflatoxin B1 (AFB1), T-2 toxins (T-2), and zearalenone (ZEN) antibodies labeled tracer, respectively. Based on the principle of spatial resolution, a rainbow “traffic light” pattern latex microspheres lateral flow immunoassay (LMs-LFIA) integrated with a portable and user-friendly smartphone-based device was first developed to detect three kinds of mycotoxins simultaneously. The cut-off values of the method for AFB1/T-2/ZEN in cereals were 1/15/40 μg kg-1, the limits of detection were 0.04/0.40/1.21 μg kg-1, respectively. The recoveries ranged from 82.1% to 107.5%, with the coefficient of variation from 3.0% to 8.1%. A parallel analysis in 26 naturally contaminated cereal samples was confirmed by commercial ELISA kits; the results showed a good correlation (R2＞0.99), indicating the practical reliability of the rainbow LMs-LFIA. This method provided a visually enjoyable, portable, and sensitive detection mode for multi-target detection of mycotoxins or other small molecule hazard factors in food.

Magnetic immunochromatographic assay with smartphone-based readout device for the on-site detection of zearalenone in cereals

In this study, a portable and quantitative immunochromatographic assay (ICA) was developed with a smartphone-based detection device as readout. The carboxyl group coated Fe 3 O 4 nanoparticles (MNPs) were synthesized by a one pot method and used as the labeled tracer. Initially, zearalenone monoclonal antibody (ZEN mAb) and MNPs conjugates were prepared and applied as the detection probe. MNPs probe produced brown band at the detection zone of the ICA. To increase the sensitivity, MNPs probe were used to enrich ZEN from sample solution, a portable detection device was designed and a user-friendly APP was self-written to quantify results. The cut-off value of the MNPs-ICA for ZEN in cereals was 2.5 μg/kg. The detection limit and quantification limit were 0.06 and 0.13 μg/kg, respectively. The recoveries ranged from 82.0 to 117.7%, with coefficient of variation from 1.3 to 10.6%. The parallel analysis results of 20 naturally contaminated cereal samples by LC-MS/MS showed that the proposed method has high accuracy. Moreover, the results of stability experiments revealed that the ICA products had a shelf life of up to 6 months. Although the feasibility is demonstrated using ZEN as a model analyte, this approach can be easily developed to be a universal analysis system and applied to detection of a wide variety of small molecule hazard factor. This study proposed a qualitative and quantitative analysis device for the food safety analysis. • MNPs was synthesized as the Ab-labeled tracer. • A portable, dual detection mode, multi-channel detection device was designed. • A user-friendly detection APP was self-programmed for quantitative analysis. • Magnetic enrichment was used to improve sensitivity and robustness of the method. • MNPs-ICA was developed to detect five zearalenone toxins in cereals.

Colloidal Au sphere and nanoflower-based immunochromatographic strips for sensitive detection of zearalenone in cereals.

Zearalenone (ZEN), also known as an F-2 toxin, is a secondary metabolite in the toxic Fusarium species with estrogen properties. ZEN and its derivatives can cause developmental and reproductive disorders in humans and other mammals. In this study, colloidal Au spheres (AuSPs) and Au nanoflowers (AuNFs) were used as signal labels to detect ZEN in cereals, and the critical factors affecting the sensitivity of the immunochromatographic strip (ICS), namely the volume of antigen, antibody, and probe quantities were optimized and compared in detail. Since the large specific surface area of AuNFs reduces the steric hindrance of proteins, it is more conducive to improving the fixation rate of antibodies and proteins. Compared with the traditional colloidal AuSP immunochromatographic strip (AuSP-ICS), the volume of the antibody used in the AuNF immunochromatographic strip (AuNF-ICS) was 0.6 times that in the AuSPs-ICS. At the same antigen volume, a lower amount of probe can achieve the desired visual detection effect and higher sensitivity. For the AuNF-ICS, the limit of detection (LOD) was as low as 0.08 ng mL-1. ZEN could be detected quickly and accurately from 0.08-10.2 ng mL-1. And the AuNF-ICS had a high degree of specificity and sensitivity to ZEN. In summary, the AuNF-ICS serves as a valuable tool in large-scale on-site detection of ZEN.

Prussian blue immunochromatography with portable smartphone-based detection device for zearalenone in cereals

In this study, we developed a prussian blue nanoparticles (PBNPs) immunochromatographic assay (ICA) integrated with smartphone-based detection device for ZEN in cereals. PBNPs, as probe labels, were synthesized with properties of controllable structure, environment friendliness, and high affinities to antibody (Ab). PBNPs-ICA quantitative analysis was performed with a hand-held smartphone-based device coupled with a user-friendly and self-programmed detection App. This integrated strategy demonstrated high sensitivity for ZEN with a cut-off value of 10 μg/kg, a detection limit of 0.12 μg/kg, a quantitation limit of 0.27 μg/kg, and recovery rates of 92.0%-105.0% and 88.0%-98.0% for maize and wheat, respectively. The results of 20 naturally contaminated cereal samples showed good correlation (R2＞0.99) between LC-MS/MS and developed system. Moreover, the stability experiment revealed that PBNPs-ICA maintained high stability and bioactivity against competitive antigen (Ag). The proposed strategy exhibited great potential for the rapid monitoring of mycotoxins or other small molecule hazards.

Determination of zearalenone in cereals by high-performance liquid chromatography and liquid chromatography-electrospray tandem mass spectrometry

Zearalenone is a mycotoxin produced mainly by fungi belonging to the genus Fusarium in foods and feeds. A rapid and accurate method to quantify zearalenone in cereals was described. The determination of zearalenone was performed using immunoaffinity column for clean-up, high-performance liquid chromatography (HPLC)/fluorescence for quantification and liquid chromatography/electrospray tandem mass spectrometry (LC/ESI-MS-MS) for confirmation. Cereal samples were extracted with acetonitrile-water (90:10, v/v) prior to a Vicam ZearalaTest™ immunoaffinity column clean-up. Zearalenone was eluted from the column with methanol and quantified by HPLC with fluorescence detection (λex = 274 nm, λem = 440 nm). A mobile phase of acetonitrile-water (50:50, v/v) and a flow rate of 1.0 mL/min-1 were used. Average recoveries of zearalenone from cereals spiked at levels of 5, 20, 100 and 200 ppb ranged from 66.4% to 96.1%. The limit of quantitation was 5 ppb. The selective determination of zearalenone was achieved by LC/MS-MS with an electrospray (ESI) ionization interface. Using the negative ion mode, the parent ion of m/z 317 and the product ion of m/z 175 were selected. The quantification limit of 3 ppb was achieved. Seven mixed cereals samples, seven corn samples, five wheat samples, five rice samples and two oat samples were analyzed. The results showed that zearalenone was detected in four corn samples ranging from 7.9 to 9.0 ppb. Using the consumption data from "Nutrition and Health Survey in Taiwan 1993-1996", the zearalenone consumption for Taiwanese adults (male and female are 0.00297 and 0.00478 μg/kg b.w. respectively) was much lower than the tolerable daily intake of 0.5 μg/kg b.w. established by JECFA.

Simultaneous quantification of aflatoxins, ochratoxin A and zearalenone in cereals by LC-MS/MS

The occurrence of mycotoxins in foods and feeds has long been recognized as a potential hazard for human and animal health due to its severe toxic and carcinogenic properties. Among various mycotoxins, aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZON) are most important because of many contamination cases in the world. In this study, a simple and rapid multiresidue method to quantify AFB 1, AFB 2, AFG 1, AFG 2, OTA and ZON was developed. The simultaneous determination of these 6 mycotoxins was performed using immunoaffinity column for clean-up and liquid chromatography/electrospray tandem mass spectrometry (LC-MS/MS) for quantification. Cereal samples were extracted with 80% methanol followed by a Vicam AOZ™ immunoaffinity column clean-up. Mycotoxins were eluted from the column with methanol and quantified using Selected Reaction Monitoring (SRM) mode in LC-MS/MS with an electrospray ionization (ESI) interface. A mobile phase of methanol-water was used. Average recoveries of AFs, OTA and ZON spiked in cereals ranged 65-95%, 66-83% and 69-86%, respectively. Good accuracy and precision results were also obtained in intra-day and inter-day analysis. The limit of quantitation (LOQ) of AFB 1, AFB 2, AFG 1, AFG 2, OTA and ZON were 0.1, 0.2, 0.1, 0.3, 0.03 and 2 ppb, respectively. Thirty-five commercial cereal products including thirteen wheat samples, seven oat samples, six rice samples and nine corn samples were analyzed. The results showed that OTA was detected in four samples ranging from 0.05 to 0.07 ppb, and ZON was detected in two samples ranging from 2.73 to 4.73 ppb. This rapid, easy and highly efficient method was successfully developed. Six common mycotoxins could be analyzed in a single 20-min run. The method could be applied to routine cereal analysis, thus dramatically shortening the analysis time.

Preparation of magnetic molecularly imprinted polymers for the identification of zearalenone in grains.

This study was based on the specific binding ability of magnetic molecularly imprinted polymers (MMIPs) combined with a high-performance liquid chromatography-fluorescence detector (HPLC-FLD) for the rapid determination of zearalenone (ZEN) in cereals. A novel magnetic molecularly imprinted polymer was prepared by surface imprinting technology. Warfarin was used as a virtual template, 3-aminopropyl triethoxysilane (APTES) was used as the functional monomer, and tetraethyl orthosilicate (TEOS) was used as the cross-linking agent. Analysis by a vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that MMIPs were prepared with a particle size about 450nm, the imprinted molecular layer accounting for 10.7% of the total mass, and saturation magnetization of about 34.54emu/g. The maximum adsorption capacity (Qmax) of the thermodynamic and kinetic adsorption experiments were 13.90mg/g and 8.71mg/g, respectively. The Langmuir model showed that the binding sites were uniformly distributed on the surface of the MMIPs. The Scatchard analysis showed that MMIPs had two types of binding sites with Qmax of 8.22mg/g and 15.37mg/g, respectively. In actual sample detection, the limit of detection (LOD) and limit of quantification (LOQ) were 0.4ng/kg and 0.9ng/kg, respectively. The sample recovery rate was 90.56-99.96%, the daytime stability was 1.35-2.87%. These results showed that MMIPs had good performance in selectively identifying ZEN and were suitable for determining ZEN in cereals.

Towards high-efficient online specific discrimination of zearalenone by using gold nanoparticles@aptamer-based affinity monolithic column

Sensitive and specific analysis of zearalenone (ZEN) mycotoxin in cereals for ensuring food safety is critical and remains challenging. Herein, a new gold nanoparticles @aptamer-functionalized hybrid affinity monolithic column was proposed and employed for online specific recognition of ZEN by HPLC. Characterization on the morphology, Brunauer–Emmett–Teller (BET) surface area mechanical stability and specific performance of the obtained affinity monolith were investigated. A super-high aptamer coverage density could reach 3636 pmol/μL, which is preferable to gain an effective analysis of ZEN with high specificity and a low interference of co-existed substances including typical α-Zearalenol (α-ZOL) and Aflatoxin B1 (AFB1). The sensitive recognition of trace ZEN was obtained with the limit of detection (LOD) as low as 0.05 ng/mL. Applied to real cereal samples, satisfactory recoveries were obtained in the range of 91.6 ± 1.4%–97.8 ± 2.6% (n = 3) in corn, 93.8 ± 3.1%–95.0 ± 3.6% (n = 3) in wheat, and 90.9 ± 4.7%–94.7 ± 3.8% (n = 3) in rice, respectively. The results on quantitative analysis were similar to that of LC–MS and better than that obtained by using immunoaffinity column (IAC) or molecularly imprinted polymer (MIP). This protocol provided an efficient access to high-efficient online specific recognition of ZEN in cereals by using such an aptamer-affinity capillary monolithic column.

Development of Lateral Flow Immunochromatographic Assays Using Colloidal Au Sphere and Nanorods as Signal Marker for the Determination of Zearalenone in Cereals.

This paper describes the development of lateral flow immunochromatographic assays (ICAs) using colloidal Au sphere (SP) and nanorods (NRs) as signal markers for the determination of zearalenone (ZEN) in cereals. The developed ICAs can detect the analyte ZEN within a short time (10 min), and achieve lower limit of detection (LOD). This is the first time that the AuNRs are used as signal probe in immune test strip for ZEN detection. For colloidal AuSP immunochromatographic analysis (AuSP-ICA), the LODs in solution and spiked cereal sample were 5.0 μg L−1 and 60 μg kg−1, and for AuNRs immunochromatographic analysis (AuNRs-ICA) the two LODs achieved 3.0 μg L−1 and 40 μg kg−1, respectively. These two proposed ICAs have minor cross-reaction to the structural analogs of ZEN, and no cross-reactivity with aflatoxin B1, T-2 toxin, ochratoxin A, deoxynivalenol, fumonisin B1. Both of the developed ICAs can specifically and sensitively detect ZEN in cereals, providing an effective strategy for rapid screening and detection of ZEN in a large number of food samples.

Black phosphorus-Au nanocomposite-based fluorescence immunochromatographic sensor for high-sensitive detection of zearalenone in cereals

Abstract Rapid and high-sensitive detection of mycotoxins is believed to be of vital importance in assuring food safety. In this study, we developed a novel fluorescence immunochromatographic sensor (ICS) for the mycotoxin of zearalenone (ZEN) in cereals. This was done by using a black phosphorus-Au nanocomposite (BP-Au) as the 2D quenching platform. Herein, gold nanoparticles (AuNPs) were directly reduced on the surface of BP nanosheets (BPNSs) to form BP-Au nanocomposites, showing higher fluorescence (quantum dots, λEm = 525 nm) quenching efficiency compared to the BPNSs and AuNPs. The fluorescence quenching efficiency of the prepared BP-Au nanocomposite reached 73.8%, which was 1.73-fold and 1.44-fold higher than AuNPs and BPNSs, respectively. The density functional theory was also successfully used to explore the formation mechanism of the BP-Au nanocomposite. By introducing the quantum dots/BP-Au signal/quencher pair, a high-sensitive fluorescence quenching ICS (B-FICS) was developed for the detection and discrimination of ZEN with the limit of detection of 0.1 μg/l in pure working buffer. This was 2.5-fold more sensitive than AuNPs-based FICS (A-FICS). The B-FICS was successfully applied in real cereals detection with the sample limit of detection of 2 μg/kg. The successful construction of B-FICS offers a novel method for a rapid and high-sensitive detection of ZEN in cereals. It also provides a new practical application of 2D BPNSs in food safety sensing.

Occurrence of deoxynivalenol and zearalenone in cereals and cereal products from Turkey

This report describes concentrations of deoxynivalenol (DON) and zearalenone (ZEA) in cereals and derived products collected in Turkey from 2015 to 2018. A total of 240 cereals and cereal products were analysed by high performance liquid chromatography coupled with photodiode array (HPLC-PDA) and fluorescence (HPLC-FLD) detectors. The analytical method performance was satisfactory, with limit of quantification (LOQ) values of 46.90–72.30 μg kg−1, and 3.50–3.70 μg kg−1 for DON and ZEA, respectively. Thirteen wheat (58–1092 μg kg−1), two maize (313–331 μg kg−1), three barley (138–973 μg kg−1), seven paddy rice (136–256 μg kg−1), three wheat flour (92–151 μg kg−1), two biscuits (31.2–71.3 μg kg−1) and only one pasta (49.3 μg kg−1) contained DON, but levels were below the EU maximum level (ML). DON was not detected in bulgur and wheat bread. ZEA was found in two wheat, three maize, eleven paddy rice and two wheat flour with a mean middle bound ZEA level of 1.34, 28.0, 42.9, and 2.66 μg kg−1, respectively. Amongst the samples contaminated with ZEA, only one paddy rice exceeded EU ML of 100 μg kg−1. However, barley, bulgur, wheat bread, pasta and biscuit products did not contain ZEA.

Anti-idiotypic nanobody-phage display-mediated real-time immuno-PCR for sensitive, simultaneous and quantitative detection of total aflatoxins and zearalenone in grains

An anti-idiotypic nanobody-phage display-mediated immuno-polymerase chain reaction (PD-IPCR) method was developed for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals. Two phages, displaying the variable domain of the heavy chain anti-idiotypic nanobody that binds aflatoxin- or zearalenone-specific monoclonal antibody (1C11 or 2D3), were used as competitors for corresponding analytes. Specific DNA sequences encoding anti-idiotypic nanobodies were used to design the primers for PCR amplification. The results indicated that detection limits for total aflatoxins and zearalenone in a sample were 0.03 and 0.09 ng mL−1, respectively. Recoveries of spiked aflatoxins and zearalenone were 80–118% and 76.7–111%, respectively. Validation results were in good agreement with the gold-standard high-performance liquid chromatography method. This report is the first to describe PD-IPCR for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals.