Publications by authors named "Dongxia Nie"

24 Publications

  • Page 1 of 1

Assessment of Human Exposure to Five Mycotoxins in China by Biomonitoring Approach.

Toxins (Basel) 2021 Oct 28;13(11). Epub 2021 Oct 28.

Key Laboratory of Protected Horticultural Technology, Institute for Agro-Food Standards and Testing Technology, Academy of Agricultural Sciences, Shanghai 201403, China.

This biomonitoring study was conducted to investigate the concentration levels of five mycotoxins in urine samples from 269 healthy volunteers living in the Yangtze River Delta, China. Alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and tentoxin (TEN) were detected in 38.3%, 48.7%, 63.9% and 23.4% of urine samples with the concentrations ranging from 0.057 to 45.8 ng/mL, 0.020 to 0.802 ng/mL, 0.050 to 80.6 ng/mL and 0.021 to 0.939 ng/mL, respectively. Altenuene (ALT) was not detected in any urine sample. Based on the urinary concentrations, the probable daily intake (PDI) values of mycotoxins were calculated, and 100%, 99.2-100%, 0.372% and 1.12% of participants exceeded the threshold of toxicological concern (TTC) values for AOH, AME, TeA and TEN, respectively. This study revealed high potential health risks related to the contaminations of major mycotoxins in China and highlighted the necessity for more toxicological studies to provide better basis for further comprehensive risk assessments.
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http://dx.doi.org/10.3390/toxins13110762DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8625692PMC
October 2021

Production of Toxins in Yellow Peach () upon Artificial Inoculation with .

Toxins (Basel) 2021 09 15;13(9). Epub 2021 Sep 15.

Institute for Agro-Food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.

The yellow peach (), an important fruit in China, is highly susceptible to infection by sp., leading to potential health risks and economic losses. In the current study, firstly, yellow peaches were artificially inoculated with . Then, the fruits were stored at 4 °C and 28 °C to simulate the current storage conditions that consumers use, and the toxins (ATs) contents from different parts of the fruits were analyzed via ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The results showed that the growth of . and the ATs production were dramatically affected by the storage temperature. At 28 °C, the fungi grew rapidly and the lesion diameter reached about 4.0 cm within 15 days of inoculation, while, at 4 °C, the fungal growth was noticeably inhibited, with no significant change in the lesion diameter. To our surprise, high contents of ATs were produced under both storage conditions even though the fungal growth was suppressed. With an increase in the incubation time, the amounts of ATs showed a steady tendency to increase in most cases. Remarkably, alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) were detected in the rotten tissue and also in the surrounding tissue, while a large amount of TeA could also be found in the healthy tissue. To the best of our knowledge, this is the first report regarding the production of ATs by the infection of sp. in yellow peach fruits via artificial inoculation under regulated conditions, and, based on the evidence herein, it is recommended that ATs be included in monitoring and control programs of yellow peach management and food safety administration.
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http://dx.doi.org/10.3390/toxins13090656DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8473313PMC
September 2021

A Multifunctional N-Doped Cu-MOFs (N-Cu-MOF) Nanomaterial-Driven Electrochemical Aptasensor for Sensitive Detection of Deoxynivalenol.

Molecules 2021 Apr 13;26(8). Epub 2021 Apr 13.

College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, China.

Deoxynivalenol (DON) is one of the most common mycotoxins in grains, causing gastrointestinal inflammation, neurotoxicity, hepatotoxicity and embryotoxicity, even at a low quantity. In this study, a facile electrochemical aptasensor was established for the rapid and sensitive determination of DON based on a multifunctional N-doped Cu-metallic organic framework (N-Cu-MOF) nanomaterial. The N-Cu-MOF, with a large specific surface area and good electrical conductivity, served not only as an optimal electrical signal probe but also as an effective supporting substrate for stabilizing aptamers through the interactions of amino (-NH) and copper. Under the optimal conditions, the proposed sensor provided a wide linear concentration range of 0.02-20 ng mL (R = 0.994), showing high sensitivity, with a lower detection limit of 0.008 ng mL, and good selectivity. The sensor's effectiveness was also verified in real spiked wheat samples with satisfactory recoveries of 95.6-105.9%. The current work provides a flexible approach for the rapid and sensitive analysis of highly toxic DON in food samples and may also be easily extended to detect other hazardous substances with alternative target-recognition aptamers.
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http://dx.doi.org/10.3390/molecules26082243DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8069659PMC
April 2021

Exposure Assessment of Multiple Mycotoxins and Cumulative Health Risk Assessment: A Biomonitoring-Based Study in the Yangtze River Delta, China.

Toxins (Basel) 2021 02 1;13(2). Epub 2021 Feb 1.

Institute for Agro-Food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-Products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.

The extensive exposure to multiple mycotoxins has been demonstrated in many countries; however, realistic assessments of the risks related to cumulative exposure are limited. This biomonitoring study was conducted to investigate exposure to 23 mycotoxins/metabolites and their determinants in 227 adults (aged 20-88 years) in the Yangtze River Delta, China. Eight mycotoxins were detected in 110 urine samples, and multiple mycotoxins co-occurred in 51/227 (22.47%) of urine samples, with deoxynivalenol (DON), fumonisin B1 (FB1), and zearalenone (ZEN) being the most frequently occurring. For single mycotoxin risk assessment, FB1, ZEN, aflatoxin B1 (AFB1), and ochratoxin A (OTA) all showed potential adverse effects. However, for the 12 samples containing DON and ZEN, in which none had a hazard risk, the combination of both mycotoxins in two samples was considered to pose potential endocrine disrupting risks to humans by hazard index (HI) method. The combined margin of exposure (MOE) for AFB1 and FB1 could constitute a potential health concern, and AFB1 was the main contributor. Our approach provides a blueprint for evaluating the cumulative risks related to different types of mycotoxins and opens a new horizon for the accurate interpretation of epidemiological health outcomes related to multi-mycotoxin exposure.
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http://dx.doi.org/10.3390/toxins13020103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7912756PMC
February 2021

A flexible assay strategy for non-glucose targets based on sulfhydryl-terminated liposomes combined with personal glucometer.

Biosens Bioelectron 2021 Mar 16;175:112884. Epub 2020 Dec 16.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, 1000 Jinqi Road, Shanghai, 201403, China. Electronic address:

The personal glucose meter (PGM) is one of the most successful point-of-care (POC) testing devices. It is simple, robust and inexpensive, but cannot be easily adapted to analytes other than glucose. We report a novel chemical conjugation-based assay strategy, using rational design of chemically-derivatized glucose-encapsulating liposomes, to repurpose a PGM, taking an important mycotoxin patulin as the model analyte. Sulfhydryl (-SH) was proposed for the first time as a specific functional group for efficient recognition of patulin. Multifunctional sulfhydryl-terminated glucose-encapsulating liposomes (G-LIP-SH) were synthesized in a simple, single step, which efficiently captured patulin by covalent bonding, and interacted strongly with [email protected] nanoparticles. Magnetic removal of nanoparticles efficiently and selectively separated patulin-derivatized from un-derivatized G-LIP-SH, permitting the latter to be lysed and the released glucose measured by PGM. The PGM signal was inversely proportional to the patulin concentration, over the range of 0.1-50 ng mL (R = 0.995) with a detection limit of 0.05 ng mL (S/N = 3). This approach overcame interference from endogenous glucose, other mycotoxins and metal ions, allowing the analysis of a wide range of sample matrices and showed high specificity, acceptable reproducibility, good accuracy and optimal applicability. Other derivatization chemistries will enable this approach to be adapted to analytes with a wide range of chemical structures, to facilitate development of rapid, portable, user-friendly and cost-effective assays applicable to diverse analytes and sample matrices.
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http://dx.doi.org/10.1016/j.bios.2020.112884DOI Listing
March 2021

Reduced graphene oxide-zinc oxide nanocomposite as dispersive solid-phase extraction sorbent for simultaneous enrichment and purification of multiple mycotoxins in Coptidis rhizoma (Huanglian) and analysis by liquid chromatography tandem mass spectrometry.

J Chromatogr A 2020 Sep 1;1630:461515. Epub 2020 Sep 1.

College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. Electronic address:

In the current study, a robust dispersive solid-phase extraction (dSPE) strategy using reduced graphene oxide-zinc oxide (rGO-ZnO) nanocomposite as the sorbent was proposed for separation, purification and enrichment of 12 mycotoxins in Coptidis rhizoma (Huanglian). The targeted mycotoxins included aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, aflatoxin M1, alternariol-methylether, mycophenolic acid, ochratoxin A, penitrem A, nivalenol, zearalenone and zearalanone. The rGO-ZnO nanocomposite was successfully synthesized through hydrothermal process by a modified Hummers method, and further characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR spectroscopy, ultraviolet-visible spectroscopy and X-ray diffraction (XRD). Several key parameters affecting the performance of the dSPE approach were extensively investigated, and after optimization, acetonitrile/water/formic acid (80/19/1, v/v/v) as the extraction solution, 2% acetonitrile as the adsorption solution, 15 mg rGO-ZnO as the sorbent, n-hexane as the washing solution, and methanol/formic acid (99/1, v/v) as the desorption solution presented an excellent purification and enrichment efficiency. Under the optimal dSPE procedure followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), adequate linearity (R ≥ 0.991), high sensitivity (limit of quantification in the range of 0.09-0.41 µg kg), acceptable recovery (70.3-105.7%) and satisfactory precision (RSD 1.4-15.0%) were obtained. The analysis of 12 selected mycotoxins was also carried out in real Coptidis rhizoma (Huanglian) samples for applicability evaluation of the established method.
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http://dx.doi.org/10.1016/j.chroma.2020.461515DOI Listing
September 2020

Dual-target electrochemical aptasensor based on co-reduced molybdenum disulfide and Au NPs (rMoS-Au) for multiplex detection of mycotoxins.

Biosens Bioelectron 2020 Feb 15;150:111894. Epub 2019 Nov 15.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China. Electronic address:

Multiple mycotoxin contamination has posed health risks in the area of food safety. In this study, co-reduced molybdenum disulfide and gold nanoparticles (rMoS-Au) were designed and used for the first time as an efficient platform endowing electrochemical electrodes with superior electron transfer rates, large surface areas and strong abilities to firmly couple with large amounts of different aptamers. After further modification with thionine (Thi) and 6-(Ferrocenyl) hexanethiol (FC6S), a platform enabling sensitive, selective and simultaneous determination of two important mycotoxins, zearalenone (ZEN) and fumonisin B1 (FB1), was achieved. The established aptasensor showed excellent linear relationships (R > 0.99) when ZEN and FB1 concentrations were in the range of 1 × 10-10 ng mL and 1 × 10-1 × 10 ng mL, respectively. High sensitivity of ZEN and FB1 with a limit of detection as low as 5 × 10 ng mL was obtained with excellent selectivity and stability. The effectiveness of the aptasensor was verified in real maize samples, and satisfactory recoveries were attained. The established platform could be easily expanded to other aptamer-based multiplex screening protocols in biochemical research and clinical diagnosis.
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http://dx.doi.org/10.1016/j.bios.2019.111894DOI Listing
February 2020

Analysis of the Carry-Over of Ochratoxin A from Feed to Milk, Blood, Urine, and Different Tissues of Dairy Cows Based on the Establishment of a Reliable LC-MS/MS Method.

Molecules 2019 Aug 2;24(15). Epub 2019 Aug 2.

Institute for Agro-Food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.

A rapid and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of ochratoxin A (OTA) and its metabolite ochratoxin α (OTα), for the first time, in dairy cow plasma, milk, urine, heart, liver, spleen, lung, and kidney. The established method was extensively validated by determining the linearity (R ≥ 0.990), sensitivity (lower limit of quantification, 0.1-0.2 ng mL), recovery (75.3-114.1%), precision (RSD ≤ 13.6%), and stability (≥83.0%). Based on the methodological advances, the carry-over of OTA was subsequently studied after oral administration of 30 μg/kg body weight OTA to dairy cows. As revealed, OTA and OTα were detected in urine, with maximal concentrations of 1.8 ng mL and 324.6 ng mL, respectively, but not in milk, plasma, or different tissues, verifying the protection effects of rumen flora against OTA exposure for dairy cows. Moreover, 100 fresh milk samples randomly collected from different supermarkets in Shanghai were also analyzed, and no positive samples were found, further proving the correctness of the in vivo biotransformation results. Thus, from the currently available data, regarding OTA contamination issues on dairy cows, no significant health risks were related to OTA exposure due to the consumption of these products.
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http://dx.doi.org/10.3390/molecules24152823DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6695942PMC
August 2019

A systematic review of plant-conjugated masked mycotoxins: Occurrence, toxicology, and metabolism.

Crit Rev Food Sci Nutr 2020 26;60(9):1523-1537. Epub 2019 Feb 26.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, China.

Masked mycotoxins are biologically modified phase II metabolites formed by plant defense mechanisms through glucosylation catalyzed by uridine diphosphate -glucosyltransferases. Most of the current reports focus on the occurrence of masked mycotoxins in Europe, America, Africa, and cover other geographic regions, e.g. China and Japan. High proportions of masked mycotoxins co-occurring with their parent forms in various cereal-based food and feedstuff could clearly increase total exposures and pose additional health risks to humans and animals. In contrast to the parent mycotoxins, the data on the toxicity of masked mycotoxins are still scarce, however, the poor existing information showed that masked mycotoxins generally exhibit significant toxicities lower than those of their parent forms, especially for deoxynivalenol-3-glucoside, which is the only thoroughly investigated masked mycotoxin. Although the lower toxicity level of masked mycotoxins, these are probably hydrolyzed into their free forms by intestinal microorganisms in the digestive tract of mammals and thus contribute to unpredicted toxicity. The metabolic characteristics of reported masked mycotoxins are species-specific. The most relevant animal model of human sensitivity, the pig, is most sensitive to masked mycotoxins. This review focuses on updates in the current knowledge on country-specific natural-occurrence data in global surveys, as well as and toxicology and metabolic investigations of masked mycotoxins.
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http://dx.doi.org/10.1080/10408398.2019.1578944DOI Listing
April 2020

Thin-layer MoS and thionin composite-based electrochemical sensing platform for rapid and sensitive detection of zearalenone in human biofluids.

Biosens Bioelectron 2019 Apr 8;130:322-329. Epub 2019 Feb 8.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China. Electronic address:

In this study, a facile electrochemical sensing platform based on thin-layer MoS and thionin (MoS-Thi) composites was constructed for the sensitive and rapid detection of zearalenone (ZEA) in human biofluids. MoS-Thi composites with a thin-layer MoS structure and large specific surface area were synthesized via a simple ultrasound exfoliation method. To further enhance the performance of the platform but without increasing the complexity of the fabrication process, ZEA antibodies were modified with Pt nanoparticles (Pt NPs) using an environmentally friendly method, where they had a much wider linear range and four times higher sensitivity compared with the original ZEA monoclonal antibody (ZEA-MAb). Under the optimal conditions, the electrochemical responses of the MoS-Thi composite-based immunosensor were linear (R = 0.9915) when the ZEA concentrations ranged from 0.01 to 50 ng mL. The proposed immunosensor could detect ZEA at concentrations as low as 0.005 ng mL with excellent selectivity. The immunosensor exhibited acceptable stability with high reproducibility and accuracy, and it was applied successfully for determining ZEA in human plasma and urine samples. Our findings indicated that the proposed MoS-Thi composite-based electrochemical sensing platform provides a new approach for the rapid and sensitive bioanalysis of ZEA, and it may also be extended to other mycotoxins for multiplex detection.
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http://dx.doi.org/10.1016/j.bios.2019.02.003DOI Listing
April 2019

Molecularly Imprinted Poly(thionine)-Based Electrochemical Sensing Platform for Fast and Selective Ultratrace Determination of Patulin.

Anal Chem 2019 03 6;91(6):4116-4123. Epub 2019 Mar 6.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture , Shanghai Academy of Agricultural Sciences , 1000 Jingqi Road , Shanghai 201403 , P. R. China.

An innovative approach based on a surface functional monomer-directing strategy for the construction of a sensitive and selective molecularly imprinted electrochemical sensor for patulin recognition is described. A patulin imprinted platinum nanoparticle (PtNP)-coated poly(thionine) film was grown on a preformed thionine tailed surface of PtNP-nitrogen-doped graphene (NGE) by electropolymerization, which provided high capacity and fast kinetics to uptake patulin molecules. Thionine acted not only as a functional monomer for molecularly imprinted polymer (MIP), but also as a signal indicator. Enhanced sensitivity was obtained by combining the excellent electric conductivity of PtNPs, NGE, and thionine with multisignal amplification. The designed sensor displayed excellent performance for patulin detection over the range of 0.002-2 ng mL (R = 0.995) with a detection limit of 0.001 ng mL for patulin. In addition, the resulting sensor showed good stability and high repeatability and selectivity. Furthermore, the feasibility of its applications has also been demonstrated in the analysis of real samples, providing novel tactics for the rational design of MIP-based electrochemical sensors to detect a growing number of deleterious substances.
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http://dx.doi.org/10.1021/acs.analchem.8b05791DOI Listing
March 2019

Development of a QuEChERS-Based UHPLC-MS/MS Method for Simultaneous Determination of Six Toxins in Grapes.

Toxins (Basel) 2019 02 1;11(2). Epub 2019 Feb 1.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.

A simple and reliable analytical method for the simultaneous determination of alternariol (AOH), altenuene (ALT), tentoxin (TEN), altenusin (ALS), tenuazonic acid (TeA), and alternariol monomethyl ether (AME) in grapes was developed by ultra-high-performance liquid chromatography⁻tandem mass spectrometry (UHPLC-MS/MS). A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure with the extraction by acetonitrile and purification by sodium chloride (0.5 g) and anhydrous magnesium sulfate (0.5 g) was established to recover the six toxins. After validation by determining the linearity (² > 0.99), recovery (77.8⁻101.6%), sensitivity (limit of detection in the range of 0.03⁻0.21 μg kg, and limit of quantification in the range of 0.09⁻0.48 μg kg), and precision (relative standard deviation (RSD) ≤ 12.9%), the analytical method was successfully applied to reveal the contamination state of toxins in grapes. Among 56 grape samples, 40 (incidence of 71.4%) were contaminated with toxins. TEN was the most frequently found mycotoxin (37.5%), with a concentration range of 0.10⁻1.64 μg kg, followed by TeA (28.6%) and AOH (26.8%). ALT (10.7%), AME (3.6%), and ALS (5.4%) were also detected in some samples. To the best of our knowledge, this is the first report about the toxins contamination in grapes in China.
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http://dx.doi.org/10.3390/toxins11020087DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6410285PMC
February 2019

Reduced graphene oxide and gold nanoparticle composite-based solid-phase extraction coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry for the determination of 9 mycotoxins in milk.

Food Chem 2018 Oct 8;264:218-225. Epub 2018 May 8.

Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China. Electronic address:

A reliable solid-phase extraction (SPE) procedure using reduced graphene oxide and gold nanoparticle (rGO/Au) composite as sorbent was proposed for purification and enrichment of aflatoxin B (AFB), aflatoxin M (AFM), ochratoxin A (OTA), zearalenone (ZEA), α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL) and β-zearalanol (β-ZAL) in milk. Main parameters affecting the performance of SPE procedure were thoroughly investigated. The optimized conditions included 2% acetonitrile in water as the loading solution, 5% methanol in water as the washing solution, and methanol/acetonitrile/formic acid (50/49/1, v/v/v) as the elution solvent. Satisfactory linearity (R ≥ 0.992), high sensitivity (limit of quantification in the range of 0.02-0.18 ng mL), adequate recovery (70.2-111.2%), and acceptable precision (RSD, 2.0-14.9%) were obtained when the optimal sample pretreatment protocol was combined with ultra-high-performance liquid chromatography-tandem mass spectrometry detection. The applicability of the validated method was further verified in real milk samples.
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http://dx.doi.org/10.1016/j.foodchem.2018.05.041DOI Listing
October 2018

Reduced Graphene Oxide-Gold Nanoparticle Nanoframework as a Highly Selective Separation Material for Aflatoxins.

Sci Rep 2017 11 3;7(1):14484. Epub 2017 Nov 3.

Institute for Agri-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China.

Graphene-based materials have been studied in many applications, owing to the excellent electrical, mechanical, and thermal properties of graphene. In the current study, an environmentally friendly approach to the preparation of a reduced graphene oxide-gold nanoparticle (rGO-AuNP) nanocomposite was developed by using L-cysteine and vitamin C as reductants under mild reaction conditions. The rGO-AuNP material showed a highly selective separation ability for 6 naturally occurring aflatoxins, which are easily adsorbed onto traditional graphene materials but are difficult to be desorbed. The specificity of the nanocomposite was evaluated in the separation of 6 aflatoxin congeners (aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, aflatoxin M1 and aflatoxin M2) from 23 other biotoxins (including, ochratoxin A, citrinin, and deoxynivalenol). The results indicated that this material was specific for separating aflatoxin congeners. The synthesized material was further validated by determining the recovery (77.6-105.0%), sensitivity (limit of detection in the range of 0.05-0.21 μg kg), and precision (1.5-11.8%), and was then successfully applied to the separation of aflatoxins from real-world maize, wheat and rice samples.
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http://dx.doi.org/10.1038/s41598-017-15210-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5670127PMC
November 2017

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method Coupled with Dispersive Solid-Phase Extraction for Simultaneous Quantification of Eight Paralytic Shellfish Poisoning Toxins in Shellfish.

Toxins (Basel) 2017 06 29;9(7). Epub 2017 Jun 29.

Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China.

In this study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for simultaneous determination of eight paralytic shellfish poisoning (PSP) toxins, including saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins (GTX1-4) and the -sulfo carbamoyl toxins C1 and C2, in sea shellfish. The samples were extracted by acetonitrile/water (80:20, /) with 0.1% formic and purified by dispersive solid-phase extraction (dSPE) with C18 silica and acidic alumina. Qualitative and quantitative detection for the target toxins were conducted under the multiple reaction monitoring (MRM) mode by using the positive electrospray ionization (ESI) mode after chromatographic separation on a TSK-gel Amide-80 HILIC column with water and acetonitrile. Matrix-matched calibration was used to compensate for matrix effects. The established method was further validated by determining the linearity (² ≥ 0.9900), average recovery (81.52-116.50%), sensitivity (limits of detection (LODs): 0.33-5.52 μg·kg; limits of quantitation (LOQs): 1.32-11.29 μg·kg) and precision (relative standard deviation (RSD) ≤ 19.10%). The application of this proposed approach to thirty shellfish samples proved its desirable performance and sufficient capability for simultaneous determination of multiclass PSP toxins in sea foods.
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http://dx.doi.org/10.3390/toxins9070206DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5535153PMC
June 2017

Determination of type A trichothecenes in coix seed by magnetic solid-phase extraction based on magnetic multi-walled carbon nanotubes coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

Anal Bioanal Chem 2016 Sep 30;408(24):6823-31. Epub 2016 Jul 30.

Institute for Agri-food Standards & Testing Technology, Shanghai Academy of Agricultural Sciences, 1000 Jinqi Road, Shanghai, 201403, China.

Magnetic solid-phase extraction (m-SPE) is a promising sample preparation approach due to its convenience, speed, and simplicity. For the first time, a rapid and reliable m-SPE approach using magnetic multi-walled carbon nanotubes (m-MWCNTs) as the adsorbent was proposed for purification of type A trichothecenes including T-2 toxins (T2), HT-2 toxins (HT-2), diacetoxyscirpenol (DAS), and neosolaniol (NEO) in coix seed. The m-MWCNTs were synthesized by assembling the magnetic nanoparticles (Fe3O4) with MWCNTs by sonication through an aggregation wrap mechanism, and characterized by transmission electron microscope. Several key parameters affecting the performance of the procedure were extensively investigated including extraction solutions, desorption solvents, and m-MWCNT amounts. Under the optimal sample preparation conditions followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), high sensitivity (limit of quantification in the range of 0.3-1.5 μg kg(-1)), good linearity (R (2) > 0.99), satisfactory recovery (73.6-90.6 %), and acceptable precision (≤2.5 %) were obtained. The analytical performance of the developed method has also been successfully evaluated in real coix seed samples. Graphical Abstract Flow chart of determination of type A trichothecenes in coix seed by magnetic solid-phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.
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http://dx.doi.org/10.1007/s00216-016-9809-0DOI Listing
September 2016

Multi-walled carbon nanotubes as solid-phase extraction sorbents for simultaneous determination of type A trichothecenes in maize, wheat and rice by ultra-high performance liquid chromatography-tandem mass spectrometry.

J Chromatogr A 2015 Dec 26;1423:177-82. Epub 2015 Oct 26.

Institute for Agro-food Standards and Testing Technology, Laboratory of Quality & Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; Laboratory of Food Analysis, Department of Bio-analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium. Electronic address:

A solid-phase extraction (SPE) procedure using multi-walled carbon nanotubes (MWCNTs) as sorbents coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for simultaneous determination of four type A trichothecenes in maize, wheat and rice for the first time. Several key parameters including the composition of sample loading solutions, washing and elution solvents were thoroughly investigated to achieve optimal SPE recoveries and efficiency. Performance of the MWCNTs materials was significantly affected by pH, and after optimization, n-hexane and 5% methanol aqueous solution as the washing solutions and methanol containing 1% formic acid as the elution solvent presented an excellent purification efficiency for the four targets in the different matrices. The method was validated by determining the linearity (R(2)≥0.992), recovery (73.4-113.7%), precision (1.2-17.1%) and sensitivity (limit of quantification in the range of 0.02-0.10μg/kg), and was further applied for simultaneous determination of type A trichothecenes in 30 samples. Although low contamination levels of type A trichothecenes in wheat, maize and rice were observed revealing mitigated risks to consumers in Shanghai, China, the developed method has proven to be a valuable tool for type A trichothecenes monitoring in complex crop matrices.
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http://dx.doi.org/10.1016/j.chroma.2015.10.068DOI Listing
December 2015

Analysis of amicarbazone and its two metabolites in grains and soybeans by liquid chromatography with tandem mass spectrometry.

J Sep Sci 2015 Jul 19;38(13):2245-52. Epub 2015 May 19.

Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, P. R. China.

A sensitive, simple and reliable analytical method based on a modified quick, easy, cheap, effective, rugged, safe sample preparation and liquid chromatography with tandem mass spectrometry detection was developed for the simultaneous determination of amicarbazone and its two major metabolites desamino amicarbazone and isopropyl-2-hydroxy-desamino amicarbazone residues in grains (rice, wheat, corn, buckwheat) and soybean. Several parameters, including liquid chromatography and tandem mass spectrometry conditions, extraction approaches and the adsorbents for clean-up, which might influence the accuracy of the method, were extensively investigated. The established method was further validated by determining the linearity (R(2) > 0.99), fortified recovery (79-118%), precision (1-12%) and sensitivity (limit of quantification, 5 μg/kg for amicarbazone and desamino amicarbazone, and 10 μg/kg for isopropyl-2-hydroxy-desamino amicarbazone). Finally, the established method was successfully applied to determine the residues of amicarbazone and its metabolites in 49 real samples of grain and soybean.
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http://dx.doi.org/10.1002/jssc.201500265DOI Listing
July 2015

A reliable liquid chromatography-tandem mass spectrometry method for simultaneous determination of multiple mycotoxins in fresh fish and dried seafoods.

J Chromatogr A 2015 Mar 31;1387:42-8. Epub 2015 Jan 31.

Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 294 Taiyuan Road, Shanghai 200031, P. R. China. Electronic address:

A reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of nine mycotoxins, i.e., aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), zearalenone (ZEN), T-2 toxin, HT2 toxin and deoxynivalenol (DON), in fresh fish (muscle and entrails) as well as dried seafoods. Special focus was given to sample pretreatment which is crucial for an accurate and reliable analytical method. With regards to the high complexity of the matrices, extraction solvent, time, and temperature as well as clean-up cartridges were optimized to improve extraction efficiency and reduce matrix effects. The optimum procedure included ultrasound-assisted extraction with acetonitrile/water/acetic acid (79/20/1, v/v/v) at 40 °C for 30 min, defatting with n-hexane and purification by Oasis HLB cartridges. The method was further validated by determining the linearity (R(2) ≥ 0.9989), sensitivity (limit of detection ≤ 2 μg/kg, limit of quantitation ≤ 3 μg/kg), recovery (72.2-119.9%) and precision (≤ 18.3%) in muscle and entrails of fresh crucian carp (Carassius carassius) as well as dried fish products. The method was proven to be suitable for its intended purposes. Mycotoxins of OTA, ZEN and AFB2 have been found in fresh fish and dried seafoods for the first time.
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http://dx.doi.org/10.1016/j.chroma.2015.01.071DOI Listing
March 2015

Gelsolin bound β-amyloid peptides(1-40/1-42): electrochemical evaluation of levels of soluble peptide associated with Alzheimer's disease.

Biosens Bioelectron 2015 Jun 18;68:115-121. Epub 2014 Dec 18.

Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China. Electronic address:

A method for the highly sensitive determination of soluable β-amyloid peptides (Aβ(1-40/1-42)) that employs a detection bioconjugate of HRP-Au-gelsolin as the electrochemical nanoprobe is presented. Contrary to previous detection notions that utilized antibodies, which could specifically recognize the N- or C-terminus of peptides, we demonstrate herein that the reported specific binding between gelsolin and Aβ might provide an alternative way to evaluate the peptides sensitively and selectively. The HRP-Au-gelsolin nanohybrid was designed by one-pot functionalization of Au nanaoparticles (NPs) with horseradish peroxidase (HRP) and gelsolin. Through a sandwich-type sensor array, soluble Aβ(1-40/1-42) were captured onto the array due to the interactions between targeted peptides and surface-confined gelsolin and electrochemical signals were amplified by abundant attachments of HRP labeled on AuNPs, which could specifically catalyse its substrate, 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to give rise to measurable signals. The proposed gelsolin-bound Aβ methodology displayed satisfactory sensitivity and wide linear range towards Aβ(1-40/1-42) with a detection limit down to 28 pM, which are verified to be sensitive-enough for the assessment of Aβ levels both in normal and Alzheimer's disease (AD) rat brains. Experimental results indicated that compared with normal group, soluble β-amyloid peptide levels in cerebrospinal fluid (CSF) and targeted brain tissues of AD rats all declined with differentiable degrees. In short, the newly unfolding strategy presents valuable information related to pathological events in brain and will exhibit a braw perspective for the early diagnosis of AD process.
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http://dx.doi.org/10.1016/j.bios.2014.12.041DOI Listing
June 2015

Cumulative health risk assessment of co-occurring mycotoxins of deoxynivalenol and its acetyl derivatives in wheat and maize: case study, Shanghai, China.

Food Chem Toxicol 2014 Dec;74:334-42

Laboratory of Quality & Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Institute for Agro-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, 1000 Jinqi Road, Shanghai 201403, China.

Humans are naturally and frequently exposed to a multitude of mycotoxins, but health risk assessments are usually performed on individual mycotoxins, which may underestimate the total risks. In this study, we assessed for the first time the cumulative health risks of concomitant exposure via dietary intake (DI) to multiple mycotoxins, namely deoxynivalenol (DON) and its acetyl derivatives of 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON), based on the concentration addition (CA) concept. A cross-sectional study was conducted in seven districts in Shanghai, China with 1269 participants and 330 wheat and maize samples analyzed. After probabilistic analysis using Monte Carlo simulation, the results showed no health risks to the population in Shanghai considering individual mycotoxins. However, if the cumulative health risks were calculated based on the combined consideration of DON with either 3-ADON or 15-ADON or both, the DI values in 95th percentile were up to 1087 ng/kg body weight/day, exceeding the Provisional Maximum Tolerable Daily Intake (PMTDI) of 1000 ng/kg body weight/day and hence representing potential health risks to the population in Shanghai. The integrated study proposed here could be a model strategy for cumulative health risk assessment on the co-occurring hazards in the fields of food safety combined with environmental contaminants.
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http://dx.doi.org/10.1016/j.fct.2014.10.018DOI Listing
December 2014

Optical study of diffuse bi-directional nanosecond pulsed dielectric barrier discharge in nitrogen.

Spectrochim Acta A Mol Biomol Spectrosc 2011 Sep 1;79(5):1896-903. Epub 2011 Jun 1.

Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024, China.

In this study, a bi-directional high voltage pulse with 20 ns rising time is employed to generate diffuse glow-like dielectric barrier discharge plasma with very low gas temperature in N2 using needle-plate electrode configuration at atmospheric pressure. Both the diffuse nanosecond pulsed dielectric barrier discharge images and the optical emission spectra of the discharge are recorded successfully under severe electromagnetic interference. The effects of pulse peak voltage, pulse repetition rate, and the concentrations of Ar and O2 on the emission intensities of NO (A2Σ→X2Π), OH (A2Σ→X2Π, 0-0), N2 (C3Πu→B3Πg, 0-0, 337.1 nm), and N2+ (B2Σu+→X2Σg+, 0-0, 391.4 nm) are investigated. The effects of the concentrations of Ar and O2 on the discharge diffuse performance are also studied. It is found that the emission intensities of NO (A2Σ→X2Π), OH (A2Σ→X2Π, 0-0), N2 (C3Πu→B3Πg, 0-0, 337.1 nm), and N2+ (B2Σu+→X2Σg+, 0-0, 391.4 nm) rise with increasing pulse peak voltage, pulse repetition rate, and the concentration of Ar, but decrease with increasing the concentration of O2. The main physicochemical processes involved are also discussed.
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http://dx.doi.org/10.1016/j.saa.2011.05.083DOI Listing
September 2011

Simultaneous determination of nitroaromatic compounds in water using capillary electrophoresis with amperometric detection on an electrode modified with a mesoporous nano-structured carbon material.

Electrophoresis 2010 Sep;31(17):2981-8

Department of Chemistry and Shanghai Key Laboratory of Green Chemistry and Chemical Process, East China Normal University, 3663 Zhongshan Road N., Shanghai, P. R. China.

In this article, a carbon disk electrode modified with mesoporous carbon material (CMK-3) was used in CE with amperometric detection system for the simultaneous determination of four types of important nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (DNT) and 1,3-dinitrobenzene (DNB). Compared with the bare carbon electrode, the CMK-3 modified electrode greatly improved the sensitivity at a relatively positive detection potential due to its excellent electrocatalytic activities, high conductivity and large effective surface area. The four analytes could be well separated and detected within 480 s. A good linear response was obtained for TNB, DNB, TNT and DNT from 8.4 to 5.0 x 10(3) μg/L, with correlation coefficients higher than 0.9992. And the detection limits were established between 3.0 and 4.7 μg/L for the four investigated nitroaromatic compounds (S/N=3). The CMK-3-modified electrode was successfully employed to analyze coking wastewater, tap water and river samples with recoveries in the range of 94.8-109.0%, and RSDs less than 5.0%. The presented results demonstrated that the CMK-3-modified carbon electrode used in CE with amperometric detection was of convenient preparation, high sensitivity and good repeatability, which could be employed in the rapid determination of practical samples.
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http://dx.doi.org/10.1002/elps.201000275DOI Listing
September 2010

Electrochemistry and electrocatalytic of hemoglobin immobilized on FDU-15-Pt mesoporous materials.

Bioelectrochemistry 2010 Oct 28;79(2):248-53. Epub 2009 Dec 28.

Department of Chemistry and Shanghai Key Laboratory of Green Chemistry and Chemical Process, East China Normal University, 3663 Zhongshan Road(N), Shanghai 200062, PR China.

In this paper, the composite films of Nafion/Hb/FDU-Pt-15/PDDA were constructed by layer-by-layer assembly technique. The FDU-15-Pt mesoporous materials were synthesized and characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The resulting films were verified by electrochemical impedance spectroscopy (EIS), cyclic voltammetry and UV-vis spectroscopy. The direct electrochemical and electrocatalytic properties of hemoglobin (Hb) in the Nafion/Hb/FDU-15-Pt/PDDA films were also investigated. A pair of stable and well-defined reversible redox peaks was observed and the formal potential of Hb Fe(III)/Fe(II) redox couple was found to be -0.324 V (vs. SCE). Based on a series of optimized conditions, the films modified electrode displayed a good electrocatalytic activity to the reduction of hydrogen peroxide (H2O2), which had linear current response from 2.0 x 10(-6) M to 6.0 x 10(-2) M with the detection limit of 1.0 x 10(-6) M (S/N=3). The apparent Michaelis-Menten constant (K(m)(app)) was determined to be 0.15 mM in the range of lower concentration of H2O2. The apparent heterogeneous electron transfer rate constant (k(s)) was 1.05 +/- 0.03 s(-1). The good sensitivity, reproducibility, excellent stability and wide linear range make Nafion/Hb/FDU-15-Pt/PDDA a promising application of the preparation of third-generation biosensor.
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http://dx.doi.org/10.1016/j.bioelechem.2009.12.008DOI Listing
October 2010
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