title: Quantum-dot submicrobead-based immunochromatographic assay for quantitative and sensitive detection of zearalenone.
abstract: Mycotoxin pollutants are commonly related to cereal products and cause fatal threats in food safety, and therefore require simple and sensitive detection. In this work, quantum-dot (QD) submicrobeads (QBs) were synthesized by encapsulating CdSe/ZnS QDs using the microemulsion technique. The resultant QBs, with approximately 2800 times brighter luminescence than the corresponding QDs, were explored as novel fluorescent probes in the immunochromatographic assay (ICA) for sensitive and quantitative detection of zearalenone (ZEN) in corns. Various parameters that influenced the sensitivity and stability of QB-based ICA (QB-ICA) were investigated and optimized. The optimal QB-ICA exhibits good dynamic linear detection for ZEN over the range of 0.125 ng/mL to 10 ng/mL with a median inhibitory concentration of 1.01±0.09 ng/mL (n=3). The detection limits for ZEN in a standard solution and real corn sample (dilution ratio of 1:30) are 0.0625 ng/mL and 3.6 µg/kg, respectively, which is much better than that of a previously reported gold nanoparticle-based ICA method. Forty-six natural corn samples are assayed using both QB-ICA and enzyme-linked immunosorbent assay. The two methods show a highly significant correlation (R(2)=0.92). Nine ZEN-contaminated samples were further confirmed with liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the QB-ICA results also exhibited good agreement with LC-MS/MS method. In brief, this work demonstrates that QB-ICA is capable of rapid, sensitive screening of toxins in food analysis, and shows great promise for point-of-care testing of other analytes.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Duan
authors.affiliation: Key Laboratory of Functional Small Organic Molecule (Ministry of Education), Jiangxi Normal University, Nanchang 330022, China.
authors.forename: Xuelan
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Jiangxi Institute of Veterinary Drug and Feedstuff Control, Nanchang 330047, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China. Electronic address: yhxiongchen@163.com.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Ocean NanoTech, LLC., San Diego, CA 92126, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Wang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D002846:Chromatography, Affinity / Q000379:methods*; D002853:Chromatography, Liquid; D002523:Edible Grain / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D057230:Limit of Detection; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D003313:Zea mays / Q000737:chemistry*; D015025:Zearalenone / Q000032:analysis*; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D015025:Zearalenone; C058667:cadmium selenide; C031238:zinc sulfide
keywords: Immunochromatographic assay; Quantitative detection; Quantum dot submicrobeads; Zearalenone