TALANTA
·
2018
·
IF 4.244
Chengke Wang,Rong Tan,Dan Chen
In this paper, a FRET (Forster resonance energy transfer) based fluorescence method was developed for the quickly detection of ochratoxin A (OTA) in agricultural products ( e.g. , flour and beer). A highly fluorescent nitrogen doped carbon dots (CD) were served as energy donor, the DNA and MCH (6-mercapto-1-hexanol) modified Ag nanoparticles were served as energy acceptor in the FRET system. OTA can be detected in a concentration range between 10 and 5000 nM, the limit of detection is 8.7 nM. This method has three advantages: (1) an enhanced fluorescent intensity can be acquired by utilizing the nitrogen doped CD synthesized by one-step approach without sophisticated modification of nanoparticles; (2) OTA detection was accomplished quickly (less than 30 min) by using MCH as assistant molecule; (3) an extended OTA detection linear range was acquired, which may facilitate the OTA detection in real agricultural samples, and is helpful for solving food safety problems.
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高影响因子
Toxins
·
2019
·Vol. 11
·期 8
·447
·
IF 3.895
Li Liu,Zafar Iqbal Tanveer,Keqiu Jiang,Qingwen Huang,Jinghui Zhang,Yongjiang Wu,Zheng Han
With the widespread contamination of ochratoxin A (OTA), it is of significant importance for detecting OTA in foods and traditional Chinese medicine (TCM). In this study, a novel label-free fluorescent aptasensor utilizing the interaction between OTA-triggered antiparallel G-quadruplex and (N-methyl-4-pyridy) porphyrin (TMPyP) for the rapid and sensitive determination of OTA was established. The fluorescence of CdTe quantum dots (QDs) could be quenched by TMPyP. In the presence of analyte (OTA), the aptamer could recognize OTA and transform from a random coil to the antiparallel G-quadruplex. The interaction between G-quadruplex and TMPyP could release CdTe QDs from TMPyP, and thus recover the fluorescence of CdTe QDs. Under optimized conditions, the detection limit of the designed aptasensor was 0.16 ng mL−1, with a linear range of 0.2 to 20 ng mL−1. Furthermore, this aptasensor showed high selectivity toward OTA against other structural analogs and other mycotoxins, and was successfully applied inAstragalus membranaceussamples. The presented aptasensor for OTA detection could be a promising tool for the field monitoring of food and TCM.Keywords:ochratoxin A;porphyrin;quantum dots;G-quadruplex aptamerKey Contribution:A label-free fluorescent aptasensor for the sensitive determination of ochratoxin A utilizing the interaction between OTA-triggered G-quadruplex and TMPyP is reported.
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PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 9
·4126-4133
·
IF 3.925
Liangrui Lv,Juanjuan Hu,Qingqing Chen,Mingming Xu,Chunyang Jing,Xiaoying Wang
Ochratoxin A (OTA) is a ubiquitous food contaminant and can cause serious harm to human health. Herein, a switchable electrochemical hairpin-aptasensor for OTA detection was established. Hairpin-DNA (h-DNA) was designed as a signal switch consisting of an anti-OTA aptamer (OTA-apt) and complementary DNA (cDNA). Gold nanospheres (GNSs) were combined with multiwalled carbon nanotubes (MWCNTs) to establish a great support interface (MWCNTs/GNSs). Meanwhile, conjugated polymer–nanoparticle composites (POPD-GNSs) were prepared and utilized to label report DNA (rDNA), forming a signal probe (POPD-GNSs-rDNA). In the presence of OTA, a configuration change was triggered and switched on the h-DNA, leading to the exposure of cDNA, which is complementary with the rDNA. Therefore, POPD-GNSs-rDNA was introduced on the electrode and produced strong electrical signals (signal on). GNSs played the role of double signal amplification in the switchable electrochemical hairpin-aptasensor. Thus, a low limit of detection of 1 pg mL−1 was obtained and the monitoring range was from 2 pg mL−1 to 1 ng mL−1. Moreover, the practicability and reliability of the constructed aptasensor was verified by detecting OTA in coffee samples. The satisfactory recovery demonstrates the potential application of this aptasensor in OTA monitoring for food security. This strategy is also applicable to the detection of other small molecule contaminants in food.
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高影响因子
FOOD CONTROL
·
2014
·
IF 2.819
Chunmei Jiang,Junling Shi,Xianqing Chen,Yanlin Liu
Fungal profiles and ochratoxin A (OTA) accumulation during wine making were investigated using five different wine grape cultivars, Cabernet Sauvignon, Pinot Noir, Merlot, Syrah and Petit Verdot and the intrinsic influences caused by sulfur dioxide, ethanol and combine effect of ethanol and reducing sugar were analyzed using Cabernet Sauvignon and inoculation of Aspergillus carbonarius . Aspergillus spp. and Penicillium spp. were found as the major fungi in all winemaking processes and were highly correlated with OTA accumulation in wine. Most fungi died and OTA production decreased after 48 h of alcoholic fermentation , being consistent with the period when ethanol accumulation increased. The addition of SO 2 significantly inhibited the growth and OTA production of A. carbonarius with complete inhibition at 500 mg/L. When the ethanol concentration in the must increased to the range of 2–4%, growth and OTA production of A. carbonarius were significantly inhibited. Reducing sugar concentration had no significant effect on the growth and OTA production of A. carbonarius within the levels changing during the winemaking. Therefore, the increase of ethanol concentration played an important role in causing the decrease of fungal contamination and OTA accumulation during winemaking.
研究领域:
食品微生物学
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真菌毒素学
·
酿酒科学
·
食品安全
·
应用微生物学
·
分子毒理学
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高影响因子
INTERNATIONAL OPHTHALMOLOGY
·
2024
·Vol. 44
·期 1
·1-10
·
IF 1.4
Fu Miao,Chen Yuanyuan,Yang Anhuai
Purpose Ochratoxin A (OTA) contamination of food and feed is a serious problem worldwide. OTA is considered a carcinogen and immunotoxic, nephrotoxic, and neurotoxic mycotoxin. The present study aims to determine the toxic effects of OTA on retinal ganglion cells (RGCs) and assess the resulting impairment of retinal function in mice. Methods RGC-5 cells were exposed to OTA (100 and 200 μg/L) for 3 days, and the mice were fed OTA-contain (100 and 200 μg/kg) diets for 4 weeks. Antioxidant indices were detected by spectrophotometer. The apoptosis of RGC-5 cells was determined by flow cytometry. Mitochondrial morphology and mitochondrial membrane potential were detected by immunofluorescence. RGC survival was determined by immunofluorescence staining with Brn3a. Flash electroretinography (ERG) was conducted to assess visual function. Results The oxidative-antioxidant balance suggested that OTA-induced severe oxidative stress, including increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels in the OTA-exposed RGC-5 cells, and the reduced activity of superoxide dismutase (SOD) and glutathione-S-transferase (GST) in the OTA exposed group. Furthermore, OTA exposure led to remarkable apoptosis in RGC-5 cells. The mitochondrial detection showed that OTA caused significant mitochondrial membrane potential reduction and mitochondrial fragmentation, which may be the cause of apoptosis of RGC-5 cells. Additionally, in vivo experiments demonstrated that OTA resulted in significant death of RGCs and subsequent retinal dysfunction in mice. Conclusion Ochratoxin A induces mitochondrial dysfunction, oxidative stress, and RGCs death in mice.
研究领域:
毒理学
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眼科学
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细胞生物学
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生物化学
·
神经科学
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高影响因子
FOOD CONTROL
·
2023
·
IF 6
Zhenyun He,Xun Yang,Shiyu Shi,Xincheng Chen,Zhichang Sun,Zhenlin Xu,Xing Liu
As one of the main mycotoxins in food, ochratoxin A (OTA) poses a serious threat to food safety and human health. Herein, a sensitive inner filter effect-based fluorescence immunoassay (IFE-FLIA) using nanobody-alkaline phosphatase fusion (Nb-ALP) and gold nanoclusters (AuNCs) was developed for the detection of OTA in pepper. Because of the IFE of p -nitrophenyl phosphate (pNPP) against the fluorescence of AuNCs and the hydrolysis of pNPP catalyzed by ALP, a fluorescence sensing platform for “turn-on” detection of Nb-ALP was first constructed with pNPP, AuNCs, and Nb-ALP. Based on the good anti-OTA activity and enzyme activity of Nb-ALP, the integration of the fluorescence sensing platform for Nb-ALP with the Nb-ALP-mediated direct competitive enzyme immunoassay for OTA implements the construction of the IFE-FLIA. Under the optimal experimental conditions, the IFE-FLIA can be finished in 85 min and has a half maximal inhibition concentration (IC 50 ) of 0.22 ng/mL with a limit of detection of 0.018 μg/kg and a linear range (IC 20 -IC 80 ) of 0.11–0.53 ng/mL for OTA. The recovery study of the spiked pepper samples and the validation of high performance liquid chromatography demonstrated the good accuracy and precision of the developed method. In conclusion, the proposed IFE-FLIA was demonstrated to be a reliable tool for the analysis of trace OTA in pepper.
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高影响因子
Analytical Methods
·
2022
·Vol. 14
·期 7
·734-740
·
IF 3.532
Mei Liu,Shasha Liu,Yue Ma,Baoxin Li
Specific and sensitive detection of hazardous mycotoxins in agricultural crops is one of the most important goals of food safety. A fluorescence biosensor for sensitive detection of ochratoxin A (OTA) was constructed via magnetic beads and the exonuclease III (Exo III)-assisted trigger DNA circle amplification approach. Exo III-assisted trigger DNA circle amplification can be utilized as an effective strategy for the sensitive detection of OTA. The employment of streptavidin labeled magnetic beads offers a manner for the accumulation and separation of the hairpin signal probe sDNA-FAM in solution. After target specific recognition, the aptamers combined with OTA were released and the remaining block DNA (bDNA) probes captured the signal probes on magnetic bead modified fluorophores. Subsequently, the enzyme digestion reaction leads to the fluorophore free solution. Exo III-assisted DNA circle amplification contributed to the high sensitivity of the presented OTA fluorescence aptasensor. The experimental results demonstrate that the aptasensor is sensitive with the limit of detection as low as 0.28 ng mL−1 for OTA, which was lower than that of the proposed aptasensors reported by the other literature on fluorescence methods. Additionally, the developed aptasensor with the diverse aptamer sequence shows promising potential applications in food monitoring.
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PubMed
高影响因子
ANALYST
·
2020
·Vol. 145
·期 6
·2420-2424
·
IF 3.978
Wenqiang Lai,Jiaqing Guo,Qingqing Wu,Yaomin Chen,Quanying Cai,Luxi Wu,Shuhan Wang,Jun Song,Dianping Tang
The aim of this study was to develop a novel colorimetric sensing method based on enzyme-regulated instant generation of Turnbull's blue, serving as a chromogenic agent, for a sensitive immunoassay for the determination of ochratoxin A (OTA). Unlike the traditional enzyme-linked immunosorbent assay (ELISA), the chromogenic reaction reported herein relies on the immediate formation of Turnbull's blue. K3[Fe(CN)6] rapidly forms a coordinate bond with iron(II), yielding a blue product. Meanwhile, glucose oxidase (GOx) catalyzes glucose hydrolysis to produce hydrogen peroxide (H2O2), which was used to inhibit the formation of Turnbull's blue by oxidizing iron(II) to iron(III). Thus, Turnbull's blue was generated in an enzyme-regulated manner. Accordingly, a competitive-type colorimetric enzyme immunoassay was established using a GOx based nanolabel. Under optimal conditions, the absorbance increased upon increasing the target OTA concentration in the range of 0.01–10 ng mL−1 with a detection limit of 8.3 pg mL−1 estimated at the 3Sblank level. The assay accuracy was validated by analyzing spiked wine samples. The present results potentially provide novel insights into the development of Turnbull's blue-based biological detection methods and colorimetric immunoassay strategies.
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PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Yue Liu,Zhiping Su,Jun Wang,Zhaoqing Gong,Haixia Lyu,Zenghong Xie
In this work, a novel molecular imprinted polymer (MIP) was prepared with “one-pot” process using acrylamide-2-methylpropanesulfonic acid (AMPS) as the functional monomer and ochratoxin A (OTA) as the template molecule. The morphology and structure of the resulted MIP were characterized, and its adsorption performance and mechanism for the analytes were also investigated. The results showed that the recovery of MIP for OTA was 84.8%, while that of non-imprinted polymer (NIP) was only 4.5%. Moreover, the recovery ratio of OTA to ochratoxin B (OTB) on MIP was 74.4 at pH 8.5, even though OTB content was 100 times as much as OTA content in the mixture of mycotoxins. The limit of detection of this method based on MIP combined with high performance liquid chromatography-fluorescence detection (HPLC-FLD) for OTA was 0.07 ng mL −1 , which was lower than 2 ng mL −1 from the European Union limit for beer. The spiked recoveries of OTA were in the range of 95.0 ± 1.5%–97.1 ± 3.1%, which showed that the obtained MIP had great potential to be applied as a specific adsorbing material for mycotoxins in complex samples.
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高影响因子
ANALYST
·
2018
·Vol. 143
·期 8
·1829-1834
·
IF 3.864
Chunxia Song,Wenwen Hong,Xiaoyu Zhang,Ying Lu
Ochratoxin A (OTA) is one of the most toxic mycotoxins and exists in various food commodities. Herein, a sensitive fluorescence method was developed for OTA detection which combines the advantages of label-free dsDNA-templated copper nanoparticles (CuNPs), high selectivity of OTA aptamer and high efficiency of exonuclease-catalyzed target recycling amplification. OTA aptamer was hybridized with its complementary DNA (cDNA), and the obtained dsDNA acted as the template for fluorescent CuNPs. In the presence of its target (OTA), the aptamer prefers to form an OTA–aptamer complex in lieu of an aptamer–DNA duplex, which results in the dissociation of the aptamer–DNA duplex. The released cDNA and aptamer could be digested into mononucleotides by the RecJf exonuclease (single-stranded DNA specific exonuclease), and the target was liberated and could participate in the next reaction cycle. The above process resulted in the degradation of a large amount of template dsDNA, which prevented the synthesis of CuNPs, thus resulting in low fluorescence of the system. Based on this strategy, a label-free and sensitive detection of OTA was developed with a low detection limit of 5 ng mL−1 (S/N = 3). Our strategy was further validated and evaluated successfully by assaying OTA in real samples. The proposed assay has great potential as an OTA quantification method for use in the food safety field.
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PubMed
高影响因子
FOOD CONTROL
·
2024
·
IF 5.6
Luyao Zhao,Jin Liu,Bing Bai,Yongpeng An,Yukun Yang,Xiaowen Wang,Xu Jing
Herein, we established a green, rapid, and sensitive method to analyze ochratoxin A (OTA) in cereals based on modified QuEChERS and enzyme-linked immunosorbent assay (ELISA). Lignocellulose is a renewable material mainly consisting of cellulose, hemicellulose, and lignin. In the modified QuEChERS, a natural deep eutectic solvent synthesized from glucose and levulinic acid derived from cellulose and hemicellulose was used as an extraction solvent to replace traditional organic solvents. Furthermore, modified lignin was used as an adsorbent to purify the extraction solution. In the magnetic bead-based ELISA, the effervescent reaction accelerated the immune competition. Additionally, magnetic beads were used to shorten the incubation and washing time, whereas gold nanoparticles were used to amplify the optical signal. This method has been successfully applied to the analysis of OTA in cereal samples. The limits of detection were 0.68–0.83 μg kg −1 . This pretreatment and detection strategy has potential application in analyzing mycotoxins.
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高影响因子
FOOD CONTROL
·
2024
·
IF 5.6
Qi Liu,Sutong Li,Zongyi Li,Caifeng Zou,Shi Feng,Juncheng Song,Jie Zhang,Xiangyang Li
Ochratoxin A (OTA), which is prone to contaminating food products, poses a significant threat to human health. To accurately detect and provide timely early warnings for OTA contamination (COTA) in food, a novel four-modal nano-biosensor detection system based on MXenes was developed in this work. MXenes is a new family of two-dimensional materials including vanadium carbide (V 2 C) MXenes, which has great potential in the field of biosensing and detection due to its large specific surface area, rich surface functional groups, and good chemical stability. By in-situ chemical etching, metal ion intercalation, and synergistic physical exfoliation techniques, V 2 C nano-materials (V 2 C-NMS) with excellent fluorescence quenching characteristics were synthesized, and V 2 C-NMS@ssDNA with excellent peroxidase like activity was constructed by functionalizing V 2 C-NMS with adapter. Based on this, a fluorescence/colorimetric biosensor for OTA was constructed, and the fluorescence/colorimetric signal output by the sensor had good linear relationship with COTA, with the detection limit (LOD) as low as 6.77 pg mL −1 . Furthermore, a fully connected artificial neural network (FCANN) was developed based on a series of RGB values obtained from the fluorescence/colorimetric mode of the biosensor, and the fluorescence/colorimetry channel of the FCANN could accurately predict the COTA of the sample on-site or remotely in just a few seconds, with the LOD as low as 7.10 pg mL −1 . Importantly, the four-mode method performed well in real sample detection, with recovery rates ranging from 95.33% to 105.79%, and the detection results of the four modalities could be mutually verified.
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高影响因子
危险品化学品经营许可证（带存储）