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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124991, 2025 Jan 05.
Article in English | MEDLINE | ID: mdl-39163773

ABSTRACT

The contamination of mycotoxins poses a serious threat to global food security, hence the urgent need for simultaneous detection of multiple mycotoxins. Herein, two SERS nanoprobes were synthesized by embedded SERS tags (4-mercaptopyridine, 4MPy; 4-mercaptobenzonitrile, TBN) into the Au and Ag core-shell structure, and each was coupled with the aptamers specific to ochratoxin A (OTA) and zearalenone (ZEN). Meanwhile, a rigid enhanced substrate Indium tin oxide glass/AuNPs/Graphene oxide (ITO/AuNPs/GO) was combined with aptamer functionalized Au@AgNPs via π-π stacking interactions between the aptamer and GO to construct a surface-enhanced Raman spectroscopy (SERS) aptasensor, thereby inducing a SERS enhancement effect for the effective and swift simultaneous detection of both OTA and ZEN. The presence of OTA and ZEN caused signal probes dissociation, resulting in an inverse correlation between Raman signal intensity (1005 cm-1 and 2227 cm-1) and the concentrations of OTA and ZEN, respectively. The SERS aptasensor exhibited wide linear detection ranges of 0.001-20 ng/mL for OTA and 0.1-100 ng/mL for ZEN, with low detection limits (LOD) of 0.94 pg/mL for OTA and 59 pg/mL for ZEN. Furthermore, the developed SERS aptasensor demonstrated feasible applicability in the detection of OTA and ZEN in maize, showcasing its substantial potential for practical implementation.


Subject(s)
Aptamers, Nucleotide , Gold , Graphite , Limit of Detection , Metal Nanoparticles , Ochratoxins , Silver , Spectrum Analysis, Raman , Zearalenone , Ochratoxins/analysis , Spectrum Analysis, Raman/methods , Gold/chemistry , Zearalenone/analysis , Metal Nanoparticles/chemistry , Aptamers, Nucleotide/chemistry , Silver/chemistry , Graphite/chemistry , Tin Compounds/chemistry , Biosensing Techniques/methods , Food Contamination/analysis
2.
Anal Chem ; 96(38): 15322-15329, 2024 Sep 24.
Article in English | MEDLINE | ID: mdl-39240680

ABSTRACT

A multiplex assay of mycotoxins in food and medicine is urgently needed and challenging due to synergistic hazards of trace mycotoxins and a lack of sensitive and user-friendly detection approaches. Herein, a cobalt DNA-inorganic hybrid superstructure (Co@DS) was developed through isothermal rolling circle amplification (RCA) for an ultrasensitive chemiluminescence (CL) imaging assay of multiple mycotoxins. Cobalt ions were enriched in the RCA product, endowing the Co@DS with a high CL catalytic property. Experimental studies elucidated the formation and CL catalytic mechanism of Co@DS. Co@DS was facilely integrated with biotinylated DNA to function as a universal platform and combined with a disposable immunosensor array chip. After a competitive immunoassay and biotin-avidin recognition, the CL signals of luminol and hydrogen peroxide, catalyzed by Co@DS captured on each testing zone of the array chip, were imaged simultaneously. Target mycotoxins can be quantitated by CL intensities. To validate the concept, the CL imaging approach was employed for joint determination of aflatoxin B1, ochratoxins A, and zearalenone. Under optimal conditions, it showed advantages including simple sample pretreatment, acceptable throughput, high accuracy, minimal sample consumption, broad linear ranges, and detection limits as low as 0.75, 0.62, and 0.61 pg mL-1, respectively. Furthermore, the approach was applied in analyzing real coix seed samples, showcasing excellent performance in effectively distinguishing qualified and contaminated medicine, revealing the great potential in managing the complex issue of mycotoxins cocontamination in food and medicine.


Subject(s)
Cobalt , DNA , Luminescent Measurements , Mycotoxins , Cobalt/chemistry , Catalysis , Mycotoxins/analysis , Mycotoxins/chemistry , Luminescent Measurements/methods , DNA/chemistry , Limit of Detection , Biosensing Techniques/methods , Luminescence , Nucleic Acid Amplification Techniques , Immunoassay/methods , Ochratoxins/analysis , Ochratoxins/chemistry
3.
Anal Chim Acta ; 1324: 343111, 2024 Oct 02.
Article in English | MEDLINE | ID: mdl-39218583

ABSTRACT

BACKGROUND: Ultrasensitive detection is crucial for the early warning and intervention of risk factors, ultimately benefiting the environment and human health. Low levels of ochratoxin A (OTA) present a hidden yet significant threat, and rapid detection via high-performing biosensors is therefore essential. RESULTS: A cascade isothermal amplification aptasensor (CIA-aptasensor) was designed for OTA detection. On the surface of a magnetic bead probe, the OTA level was converted into positively correlated trigger cDNA through its competitive binding with OTA-Apt. The released trigger cDNA activated catalytic hairpin assembly followed by coupling with a hybridization chain reaction to achieve CIA. After adding graphene oxide and SYBR Green I, the background interference was eliminated to specifically obtain OTA-related fluorescence. The ultrasensitive limit of detection was 0.22 pg mL-1, an improvement of 1368-fold over conventional enzyme-linked aptamer sorbent assay by the same OTA-Apt, demonstrating satisfactory reliability and practicability. Thus, the CIA-aptasensor provides an enzyme- and label-free simplified homogeneous system with minimal background interference using isothermal conditions. SIGNIFICANCE: This study provides a polymerase chain reaction-like approach for enhancing the sensitivity and performance of a biosensor, which could be extended for the application of CIA and label-free signaling strategy to other risk factors.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Limit of Detection , Nucleic Acid Amplification Techniques , Ochratoxins , Ochratoxins/analysis , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Nucleic Acid Amplification Techniques/methods , Graphite/chemistry
4.
J Food Prot ; 87(9): 100342, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39122212

ABSTRACT

The production of raisins, a method of grape preservation since antiquity, has evolved with various drying techniques that significantly impact the quality and safety of the final product. This study evaluates the efficacy of a solar indirect dryer compared to traditional sun-drying methods for drying Centennial Seedless and Sultanina grape cultivars in Crete, Greece. Key parameters assessed include environmental conditions, drying time, grape color, fungal contamination, and Ochratoxin A (OTA) levels. Grapes were dried in a controlled solar chamber and under open sun conditions. The solar chamber maintained higher average temperatures (34 °C) and lower relative humidity (39.7%) than outside conditions (24.2 °C and 58.7%, respectively), significantly reducing the drying time from 12 to 7 days. Raisins dried in the solar chamber exhibited improved color quality, with higher Lightness (L*), Hue Angle (h), and Chroma (C*) values, attributed to minimized enzymatic and nonenzymatic browning. Mycological analysis revealed a substantial reduction in Aspergillus section Nigri contamination in chamber-dried raisins, with mean colony-forming units per gram significantly lower than those of sun-dried raisins. Consequently, OTA levels were also significantly reduced in chamber-dried raisins, with Centennial Seedless showing a mean concentration of 1.01 µg/kg compared to 2.66 µg/kg in sun-dried samples, and Sultanina showing 0.70 µg/kg versus 2.05 µg/kg, respectively. These findings underscore the advantages of using solar indirect dryers to enhance drying efficiency, improve color quality, and reduce fungal and OTA contamination, highlighting the importance of adopting controlled drying technologies for safer, higher-quality raisins.


Subject(s)
Vitis , Desiccation , Humans , Food Handling/methods , Food Contamination/analysis , Food Contamination/prevention & control , Ochratoxins/analysis , Food Preservation/methods , Fruit/microbiology
5.
Food Chem ; 461: 140842, 2024 Dec 15.
Article in English | MEDLINE | ID: mdl-39173256

ABSTRACT

A GPE-PET (graphene-polyethylene terephthalate) bipolar electrode-electrochemiluminescence (BPE-ECL) platform was developed for ochratoxin A (OTA) detection. PET served as the electrode sheet substrate, and GPE was drop-coated onto the surface of PET to form a conductive line. On the functional sensing interface, the thiol (-SH) modified OTA aptamer (OTA-Aptamer) are fixed on the surface of the gold-plated cathode through AuS bonds. The efficient electron transfer ability of methylene blue (MB) made the anode ECL signal strong. Due to competition between OTA and MB with OTA-Aptamer, leading to a decrease in ECL intensity of the [Ru(bpy)3]2+/TPA system on the BPE anode. Under optimized conditions, the GPE-PET BPE-ECL biosensor displayed superior sensitivity for OTA with a detection limit of 2 ng mL-1 and a wide linear concentration range of 5-100 ng mL-1. This method could be further applied to detect various toxins and had broad application prospects.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Electrodes , Luminescent Measurements , Ochratoxins , Ochratoxins/analysis , Biosensing Techniques/instrumentation , Luminescent Measurements/instrumentation , Luminescent Measurements/methods , Electrochemical Techniques/instrumentation , Graphite/chemistry , Food Contamination/analysis , Polyethylene Terephthalates/chemistry , Limit of Detection
6.
Anal Chim Acta ; 1319: 342982, 2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39122269

ABSTRACT

BACKGROUND: The importance of multi-target simultaneous detection lies in its ability to significantly boost detection efficiency, making it invaluable for rapid and cost-effective testing. Photoelectrochemical (PEC) sensors have emerged as promising candidates for detecting harmful substances and biomarkers, attributable to their unparalleled sensitivity, minimal background signal, cost-effectiveness, equipment simplicity, and outstanding repeatability. However, designing an effective multi-target detection strategy remains a challenging task in the PEC sensing field. Consequently, there is a pressing need to address the development of PEC sensors capable of simultaneously detecting multiple targets. RESULTS: CdIn2S4/V-MoS2 heterojunctions were successfully prepared via a hydrothermal method. These heterojunctions exhibited a high photocurrent intensity, representing a 1.53-fold enhancement compared to CdIn2S4 alone. Next, we designed a multi-channel aptasensing chip using ITO as the substrate. Three working electrodes were created via laser etching and subsequently modified with CdIn2S4/V-MoS2 heterojunctions. Thiolated aptamers were then self-assembled onto the CdIn2S4/V-MoS2 heterojunctions via covalent bonds, serving as recognition tool. By empolying the CdIn2S4/V-MoS2 heterojunctions as the sensing platform and aptamers as recognition tool, we successfully developed a disposable aptasensing chip for the simultaneous PEC detection of three typical mycotoxins (aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN)). This aptasensing chip exhibited wide detection range for AFB1 (0.05-50 ng/mL), OTA (0.05-500 ng/mL), and ZEN (0.1-250 ng/mL). Furthermore, it demonstrated ultra-low detection limits of 0.017 ng/mL for AFB1, 0.016 ng/mL for OTA, and 0.033 ng/mL for ZEN. SIGNIFICANCE AND NOVELTY: The aptasensing chip stands out for its cost-effectiveness, simplicity of fabrication, and multi-channel capabilities. The versatility and practicality enable it to serve as a powerful platform for designing multi-channel PEC aptasensors. With its ability to detect multiple targets with high sensitivity and specificity, the aptasensing chip holds immense potential for applications across diverse fields, such as environmental monitoring, clinical diagnostics, and food safety monitoring, where multi-target detection is crucial.


Subject(s)
Aptamers, Nucleotide , Disulfides , Electrochemical Techniques , Molybdenum , Semiconductors , Molybdenum/chemistry , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Aptamers, Nucleotide/chemistry , Disulfides/chemistry , Limit of Detection , Nanostructures/chemistry , Photochemical Processes , Mycotoxins/analysis , Biosensing Techniques , Cadmium Compounds/chemistry , Ochratoxins/analysis
7.
J Hazard Mater ; 477: 135264, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-39032175

ABSTRACT

Nontoxic substitutes to mycotoxins can facilitate the development of eco-friendly immunoassays. To explore a novel nontoxic substitute to ochratoxin A (OTA), this study screened shark anti-idiotypic variable new antigen receptors (VNARs) against the alpaca anti-OTA nanobody Nb28 through phage display. After four rounds of biopanning of a naïve VNAR phage display library derived from six adult Chiloscyllium plagiosum sharks, one positive clone, namely, P-3, was validated through a phage enzyme-linked immunosorbent assay (phage ELISA). The recombinant anti-idiotypic VNAR AId-V3 was obtained by prokaryotic expression, and the interactions between Nb28 and AId-V3 were investigated via computer-assisted simulation. The affinity of AId-V3 for Nb28 and its heptamer Nb28-C4bpα was measured using Biacore assay. Combining Nb28-C4bpα with AId-V3, a novel direct competitive ELISA (dcELISA) was developed for OTA analysis, with a limit of detection of 0.44 ng/mL and a linear range of 1.77-32.25 ng/mL. The good selectivity, reliability, and precision of dcELISA were confirmed via cross-reaction analysis and recovery experiments. Seven commercial pepper powder samples were tested using dcELISA and validated using high-performance liquid chromatography. Overall, the shark anti-idiotypic VNAR was demonstrated as a promising nontoxic substitute to OTA, and the proposed method was confirmed as a reliable tool for detecting OTA in food.


Subject(s)
Camelids, New World , Enzyme-Linked Immunosorbent Assay , Ochratoxins , Sharks , Single-Domain Antibodies , Ochratoxins/analysis , Ochratoxins/immunology , Sharks/immunology , Animals , Camelids, New World/immunology , Single-Domain Antibodies/immunology , Single-Domain Antibodies/chemistry , Antibodies, Anti-Idiotypic/immunology , Receptors, Antigen/immunology
8.
Meat Sci ; 217: 109605, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39068743

ABSTRACT

The European Union legislation regarding ochratoxin A (OTA) in various foodstuffs has changed relatively recently. Nevertheless, the legislation does not regulate OTA in any meat and meat-derived products. In this legislation update, the European Commission requested new studies, including, besides others, the presence of OTA in hams, which raises the concern that its consumption may pose a potential risk of exposure to OTA. This study aims to investigate OTA in a total of 195 samples of air-dry-cured hams acquired at the Czech market from January to June 2023. The analytical technique of high-performance liquid chromatography in combination with a fluorescence detector with pre-treatment employing immunoaffinity columns was used to determine OTA. OTA was found in 93 (48%) samples of air-dry-cured ham, with the OTA concentration reaching up to 14.58 ng/g. Due to the current absence of regulation limits, the results of this study were compared with the Italian maximum limit of 1 ng/g regulating OTA in porcine meat and byproducts. The Italian OTA maximum limit was exceeded in 22 (11%) samples. This study shows that the population of the Czech Republic is exposed to OTA from this pork byproduct. It is essential to set an OTA regulatory limit for meat and food produced from it to protect human health.


Subject(s)
Food Contamination , Meat Products , Ochratoxins , Ochratoxins/analysis , Animals , Food Contamination/analysis , Meat Products/analysis , Czech Republic , Swine , Chromatography, High Pressure Liquid , Pork Meat/analysis
9.
Food Chem ; 460(Pt 2): 140590, 2024 Dec 01.
Article in English | MEDLINE | ID: mdl-39067424

ABSTRACT

Ochratoxin A (OTA) is a nephrotoxin that contaminates grains in storage. Moisture and temperature sensors give delayed responses due to their slow kinetic movement within the silo. This study examines if CO2 production could predict OTA contamination and identify storage conditions exceeding the maximum limit (5 µg/kg). The impact of water activity levels (0.70-0.90 aw), temperatures (15 and 20 °C), and storage duration on (a)Penicillium verrucosum population, (b)CO2 respiration rates (RR), and (c)ochratoxins concentrations in stored wheat was investigated. 96 samples were analysed for ochratoxins with LCMS-MS. RR was >7 times higher at wetter conditions than at drier aw levels. A positive correlation between CO2, OTA, OTB, and OTα was observed at the wettest conditions. OTA exceeded the limit at >0.80 aw (16% moisture content) with RR > 0.01 mg CO2 kg-1 h-1. The knowledge of the RR of stored grain would alert grain farmers/managers to improve grain storage management.


Subject(s)
Carbon Dioxide , Food Contamination , Ochratoxins , Penicillium , Temperature , Triticum , Water , Triticum/chemistry , Triticum/microbiology , Triticum/metabolism , Ochratoxins/analysis , Ochratoxins/metabolism , Carbon Dioxide/metabolism , Carbon Dioxide/analysis , Penicillium/metabolism , Penicillium/growth & development , Food Contamination/analysis , Water/metabolism , Water/analysis , Water/chemistry , Food Storage
10.
Article in English | MEDLINE | ID: mdl-39008630

ABSTRACT

This study reviews global levels of ochratoxin A (OTA) in infant formula and cereal-based foods, using Monte Carlo simulation to assess risks. The review found 24 studies on global OTA levels in infant food and cereal-based products, using databases including PubMed, Scopus, Web of Science and Embase until March 2024. We estimated OTA exposure in infant food based on concentration, intake and body weight. The exposure and hazard quotient margin were calculated using BMDL10 and TDI values. Monte Carlo simulation evaluated human health risks from OTA in infant formula and cereal-based foods. A global study from 14 countries shows varying levels, surpassing EU limits in Tunisia, Ecuador, the USA, and generally in Africa, notably in infant cereals, which had higher levels than formula. Globally, OTA was present in 29.3% of the 3348 samples analyzed, with Lebanon at 95.2% and Brazil at 0%. Analysis indicates only non-carcinogenic risk for infants. While health risks for infants are mostly low, ongoing research and monitoring are vital to minimize OTA exposure in infant food.


Subject(s)
Edible Grain , Food Contamination , Infant Food , Infant Formula , Ochratoxins , Humans , Infant , Edible Grain/chemistry , Edible Grain/microbiology , Food Contamination/analysis , Infant Food/analysis , Infant Food/microbiology , Infant Formula/analysis , Infant Formula/chemistry , Infant Formula/microbiology , Ochratoxins/analysis , Risk Assessment
11.
Food Chem ; 460(Pt 1): 140398, 2024 Dec 01.
Article in English | MEDLINE | ID: mdl-39032299

ABSTRACT

Co-contamination of multiple mycotoxins produces synergistic toxic effects, leading to more serious hazards. Therefore, the simple, rapid and accurate simultaneous detection of multiple mycotoxins is crucial. Herein, a three-channel aptamer-based lateral flow assay (Apt-LFA) was established for the detection of aflatoxin M1 (AFM1), aflatoxin B1 (AFB1) and ochratoxin A (OTA). The multi-channel Apt-LFA utilized gold­iridium nanozyme to catalyze the chromogenic substrate, which effectively achieved signal amplification. Moreover, the positions and lengths of the complementary sequences were screened by changes in fluorescence intensity. After grayscale analysis, the semi-quantitative results showed that the detection limits of AFM1, AFB1 and OTA were 0.39 ng/mL, 0.36 ng/mL and 0.82 ng/mL. The recoveries of the multiplexed competitive sensors in complex matrices of real samples were 93.33%-97.01%, 95.72%-102.67%, and 106.88%-109.33%, respectively. In conclusion, the assembly principle of the three-channel Apt-LFA is simple, which can provide a new idea for the simultaneous detection of small molecule targets.


Subject(s)
Aflatoxin B1 , Food Contamination , Mycotoxins , Ochratoxins , Food Contamination/analysis , Mycotoxins/analysis , Mycotoxins/chemistry , Aflatoxin B1/analysis , Ochratoxins/analysis , Limit of Detection , Gold/chemistry , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Aptamers, Nucleotide/chemistry , Aflatoxin M1/analysis
12.
Meat Sci ; 216: 109591, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38991481

ABSTRACT

Penicillium nordicum is the main ochratoxin A (OTA)-producing species on the surface of dry-fermented sausages, such as the "chorizo". New antifungal strategies are being developed using biocontrol agents (BCAs), such as plant extracts and native microorganisms. This work aimed to evaluate the antiochratoxigenic capacity and the causative modes of action of BCAs (rosemary essential oil (REO), acorn shell extract and the yeast Debaryomyces hansenii (Dh)) in a "chorizo"-based medium (Ch-DS). BCAs were inoculated on Ch-DS together with P. nordicum and incubated at 12 °C for 15 days to collect mycelia for OTA analyses and comparative proteomics. Both REO and Dh alone decreased OTA accumulation up to 99% and affected the abundance of P. nordicum proteins linked to cell wall organisation, synthesis of OTA-related metabolites and ergosterol synthesis. It is worth highlighting the increased abundance of an amidase by REO, matching with the decrease in OTA. The use of REO and Dh as BCAs could be an effective strategy to reduce the OTA hazard in the meat industry. Based on their not fully coincident modes of action, their combined application could be of interest in "chorizo" to maximise their potential against ochratoxigenic strains.


Subject(s)
Meat Products , Ochratoxins , Penicillium , Plant Extracts , Proteomics , Penicillium/drug effects , Meat Products/microbiology , Meat Products/analysis , Ochratoxins/analysis , Proteomics/methods , Plant Extracts/pharmacology , Plant Extracts/chemistry , Animals , Debaryomyces , Food Microbiology , Oils, Volatile/pharmacology , Cistus/chemistry , Antifungal Agents/pharmacology , Fungal Proteins/metabolism
13.
J Hazard Mater ; 476: 135111, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-38981231

ABSTRACT

Covalent organic frameworks (COFs) are attractive materials for sample pretreatment due to their tunable structures and functions. However, the precise recognition of contaminant in complex environmental matrices by COFs remains challenging owing to their insufficient specific active sites. Herein, we report Co2+ coordination-assisted molecularly imprinted flexible COF (MI-COF@Co2+) for selective recognition of ochratoxin A (OTA). The MI-COF@Co2+ was prepared via one-step polymerization of 3,3-dihydroxybenzidine, 2,4,6-tris(4-formylphenoxy)- 1,3,5-triazine, Co2+ and template. The flexible units endowed COFs with the self-adaptable ability to regulate the molecular conformation and coordinate with Co2+ to locate the imprinted cavities. The coordination interaction greatly improved the adsorption capacity and selectivity of MI-COF@Co2+ for OTA. The prepared MI-COF@Co2+ was used as solid phase extraction adsorbent for high-performance liquid chromatography determination of OTA with the detection limit of 0.03 ng mL-1 and the relative standard deviation of < 2.5 %. In addition, this method permitted interference-free determination of OTA in real samples with recovery from 89.5 % to 102.8 %. This work provides a simple way to improve the selectivity of COFs for the determination of hazardous compounds in complex environments.


Subject(s)
Cobalt , Metal-Organic Frameworks , Molecular Imprinting , Ochratoxins , Solid Phase Extraction , Ochratoxins/analysis , Ochratoxins/chemistry , Solid Phase Extraction/methods , Metal-Organic Frameworks/chemistry , Adsorption , Cobalt/chemistry , Chromatography, High Pressure Liquid , Limit of Detection
14.
J Hazard Mater ; 476: 135112, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-38981234

ABSTRACT

In light of the significant risks that mycotoxins posed to public health and environmental safety, this research developed an adsorbent MIPs/Apt/AuNPs@ZIF-67 (MA-AZ) utilizing a dual-recognition approach combining molecularly imprinted polymers (MIPs) and aptamer (Apt). This innovative method enabled the effective and highly selective recognition and enrichment of ochratoxin A (OTA). ZIF-67 was utilized as a carrier with a substantial specific surface area, and gold nanoparticles (AuNPs) were loaded on its surface to fix the thiol-modified Apt on the surface of the carrier. Then, an initiator was used to initiate a polymerization reaction, and the generated MIPs coated Apt/AuNPs@ZIF-67, thereby synthesizing the MA-AZ with a "synergistic recognition" effect. The Apt significantly increased the number of recognition sites within the imprinted cavities, and MIPs played roles in identifying targets, fixing and protecting Apt. The combination of the both produced the effect of "1+1>2". The study on the adsorption performance of MA-AZ found that the adsorption capacity of MA-AZ could reach 65.1 mg/g, and the imprinted factor was 5.48. In addition, MA-AZ exhibited excellent stability, specificity, reusability and recovery rate. Thus, this study offers valuable insights for the recognition and enrichment of hazardous substances, and helps to promote the rapid development of safety detection.


Subject(s)
Aptamers, Nucleotide , Gold , Metal Nanoparticles , Molecularly Imprinted Polymers , Ochratoxins , Ochratoxins/chemistry , Ochratoxins/analysis , Aptamers, Nucleotide/chemistry , Adsorption , Molecularly Imprinted Polymers/chemistry , Metal Nanoparticles/chemistry , Gold/chemistry , Molecular Imprinting , Limit of Detection , Solid Phase Extraction/methods
15.
Food Chem ; 456: 140007, 2024 Oct 30.
Article in English | MEDLINE | ID: mdl-38861864

ABSTRACT

Developing an efficient method for screening Ochratoxin A (OTA) in agriculture products is vital to ensure food safety and human health. However, the complex food matrix seriously affects the sensitivity and accuracy. To address this issue, we designed a novel molecularly imprinted polymer (MIP) electrochemical sensor based on multiwalled carbon nanotube-modified niobium carbide (Nb2C-MWCNTs) with the aid of the density functional theory (DFT). In this design, a glassy carbon electrode (GCE) was first modified by Nb2C-MWCNTs heterostructure. Afterward, the MIP layer was prepared, with ortho-toluidine as a functional monomer selected via DFT and OTA acting as a template on the surface of Nb2C-MWCNTs/GCE using in-situ electropolymerization. Electrochemical tests and physical characterization revealed that Nb2C-MWCNTs improved the sensor's active surface area and electron transmission capacity. Nb2C-MWCNTs had a good synergistic effect on MIP, endowing the sensor with high sensitivity and specific recognition of OTA in complex food matrix systems. The MIP sensor showed a wide linear range from 0.04 to 10.0 µM with a limit of detection (LOD) of 3.6 nM. Moreover, it presented good repeatability and stability for its highly antifouling effect on OTA. In real sample analysis, the recoveries, ranging from 89.77% to 103.70%, agreed well with the results obtained by HPLC methods, suggesting the sensor has good accuracy and high potential in practical applications.


Subject(s)
Electrochemical Techniques , Food Contamination , Limit of Detection , Molecular Imprinting , Molecularly Imprinted Polymers , Nanotubes, Carbon , Ochratoxins , Ochratoxins/analysis , Ochratoxins/chemistry , Nanotubes, Carbon/chemistry , Electrochemical Techniques/instrumentation , Food Contamination/analysis , Molecularly Imprinted Polymers/chemistry , Electrodes
16.
Article in English | MEDLINE | ID: mdl-38870338

ABSTRACT

The study aimed to screen fungal diversity and ochratoxin A levels on culinary spice and herb samples sold in open-air markets and supermarkets in Nairobi County, Kenya. All herbs were grown in Kenya, while locally-produced and imported spices were purchased from both types of retail outlet. The results showed a high frequency of Aspergillus and Penicillium species contaminating the samples. The isolated species included Aspergillus ochraceous, Aspergillus nomiae, Aspergillus niger, Aspergillus flavus, Aspergillus ustus, Aspergillus terrus, Aspergillus nidulans, Aspergillus clavutus, Penicillium crustosum, Penicillium expansum, Penicillium brevicompactum, Penicillium glabrum, Penicillium thomii, Penicillium citrinum, Penicillium polonicum, and Cladosporium cladosporioides. Total fungal count on spice and herb samples collected from various sources varied between 6 and 7 CFU/mL. Of imported spices, garlic had the highest fungal diversity, while cardamom had the least. For spices from both open market and supermarket outlets, cloves had the highest fungal diversity, while white pepper had the least. For the herbs sampled from the open markets, basil was the most contaminated, while sage was the least. In supermarket samples, parsley, sage, and mint had the highest fungal diversity, and bay had the least. The results indicate the contamination of spices and herbs with OTA at high concentrations. The calibration curve was saturated at 40 µg/kg; with samples of garlic, cinnamon, red chili, basil, thyme, mint, sage, and parsley having levels above this. Of the spices, imported ginger had the highest OTA levels (28.7 µg/kg), while turmeric from the open market had the least, 2.14 µg/kg. For herb samples, parsley from the open market had the highest OTA levels at 29.4 µg/kg, while marjoram from the open market had the lowest at 6.35 µg/kg. The results demonstrate the presence of mycotoxigenic fungi and OTA contamination of marketed culinary herbs and spices beyond acceptable limits. Hence, there is a need for informed and sustainable mitigation strategies aimed at reducing human exposure in Kenya to OTA mycotoxicosis through dietary intake of spices and herbs.


Subject(s)
Food Contamination , Ochratoxins , Penicillium , Spices , Ochratoxins/analysis , Spices/analysis , Spices/microbiology , Kenya , Food Contamination/analysis , Penicillium/isolation & purification , Aspergillus/isolation & purification
17.
Toxins (Basel) ; 16(6)2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38922171

ABSTRACT

Viticulture has been an important economic sector for centuries. In recent decades, global wine production has fluctuated between 250 and almost 300 million hectoliters, and in 2022, the value of wine exports reached EUR 37.6 billion. Climate change and the associated higher temperatures could favor the occurrence of ochratoxin A (OTA) in wine. OTA is a mycotoxin produced by some species of the genera Aspergillus and Penicillium and has nephrotoxic, immunotoxic, teratogenic, hepatotoxic, and carcinogenic effects on animals and humans. The presence of this toxin in wine is related to the type of wine-red wines are more frequently contaminated with OTA-and the geographical location of the vineyard. In Europe, the lower the latitude, the greater the risk of OTA contamination in wine. However, climate change could increase the risk of OTA contamination in wine in other regions. Due to their toxic effects, the development of effective and environmentally friendly methods to prevent, decontaminate, and degrade OTA is essential. This review summarises the available research on biological aspects of OTA prevention, removal, and degradation.


Subject(s)
Food Contamination , Ochratoxins , Wine , Ochratoxins/analysis , Wine/analysis , Food Contamination/analysis , Food Contamination/prevention & control , Animals , Humans
18.
Talanta ; 278: 126450, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38908138

ABSTRACT

In response to the pressing need for highly efficient simultaneous detection of multiple mycotoxins, which are often found co-occurring in food raw materials and feed, an MXene-based electrochemical aptasensor array (MBEAA) was developed. This aptasensor array utilizes high-specificity aptamers as recognition elements, enabling the capture of electrical signal changes in the presence of target mycotoxins. Based on this platform, a multi-channel portable electrochemical device, enabling rapid, cost-effective, and simultaneous detection of aflatoxin B1 (AFB1), ochratoxin A (OTA), and zealenone (ZEN) was further developed. The developed system boasts a wide detection range of 1.0 × 10-1 to 10.0 ng mL-1, with remarkable performance characterized by ultra-low detection limits of 41.2 pg mL-1, 27.6 pg mL-1, and 33.0 pg mL-1 for AFB1, OTA, and ZEN, respectively. Successfully applied in corn samples, this method offers a portable, easy-to-operate, and cost-effective solution for simultaneous multi-mycotoxin detection. Moreover, the application of the self-developed detection system could be expanded for simultaneous detection of many different targets when their specific aptamers or antibodies were available.


Subject(s)
Aflatoxin B1 , Aptamers, Nucleotide , Biosensing Techniques , Electrochemical Techniques , Mycotoxins , Aptamers, Nucleotide/chemistry , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Mycotoxins/analysis , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Aflatoxin B1/analysis , Zea mays/chemistry , Limit of Detection , Ochratoxins/analysis
19.
Food Chem ; 457: 140190, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-38924915

ABSTRACT

An innovative aptasensor incorporating MoS2-modified bicolor quantum dots and a portable spectrometer, designed for the simultaneous detection of ochratoxin A (OTA) and aflatoxin B1 (AFB1) in corn was developed. Carbon dots and CdZnTe quantum dots were as nano-donors to label OTA and AFB1 aptamers, respectively. These labeled aptamers were subsequently attached to MoS2 receptors, enabling fluorescence resonance energy transfer (FRET). With targets, the labeled aptamers detached from the nano-donors, thereby disrupting the FRET process and resulting in fluorescence recovery. Furthermore, a portable dual-mode fluorescence detection system, complemented with customized python-based analysis software, was developed to facilitate rapid and convenient detection using this dual-color FRET aptasensor. The developed host program is connected to the spectrometer and transmits data to the cloud, enabling the device to have Internet of Things (IoT) characteristics. Connected to the cloud, this IoT-enabled device offers convenient and reliable fungal toxin detection for food safety.


Subject(s)
Aflatoxin B1 , Aptamers, Nucleotide , Biosensing Techniques , Fluorescence Resonance Energy Transfer , Food Contamination , Ochratoxins , Quantum Dots , Software , Fluorescence Resonance Energy Transfer/instrumentation , Ochratoxins/analysis , Aptamers, Nucleotide/chemistry , Biosensing Techniques/instrumentation , Food Contamination/analysis , Aflatoxin B1/analysis , Quantum Dots/chemistry , Zea mays/chemistry , Fluorescence , Tellurium/chemistry , Disulfides , Molybdenum
20.
Environ Toxicol Pharmacol ; 109: 104489, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38844151

ABSTRACT

Among cereal contaminants, mycotoxins are of concern due to their importance in terms of food and feed safety. The difficulty in establishing a diagnosis for mycotoxicosis relies on the fact that the effects are most often subclinical for chronic exposure and the most common scenario is multi-contamination by various toxins. Mycotoxin co-occurrence is a major food safety concern as additive or even synergic toxic impacts may occur, but also regarding current regulations as they mainly concern individual mycotoxin levels in specific foods and feed in the food chain. However, due to the large number of possible mycotoxin combinations, there is still limited knowledge on co-exposure toxicity data, which depends on several parameters. In this context, this systematic review aims to provide an overview of the toxic effects of two regulated mycotoxins, namely ochratoxin A and fumonisin B1. This review focused on the 2012-2022 period and analysed the occurrence in Europe of the selected mycotoxins in different food matrices (cereals and cereal-derived products), and their toxic impact, alone or in combination, on in vitro intestinal and hepatic human cells. To better understand and evaluate the associated risks, further research is needed using new approach methodologies (NAM), such as in vitro 3D models. KEY CONTRIBUTION: Cereals and their derived products are the most important food source for humans and feed for animals worldwide. This manuscript is a state of the art review of the literature over the last ten years on ochratoxin A and fumonisin B1 mycotoxins in these products in Europe as well as their toxicological effects, alone and in combination, on human cells. Future perspectives and some challenges regarding the assessment of toxicological effects of mycotoxins are also discussed.


Subject(s)
Edible Grain , Food Contamination , Fumonisins , Ochratoxins , Ochratoxins/toxicity , Ochratoxins/analysis , Fumonisins/toxicity , Fumonisins/analysis , Edible Grain/chemistry , Humans , Food Contamination/analysis , Europe , Animals
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