title: Antibody-Free Colorimetric Detection of Total Aflatoxins in Rice Based on a Simple Two-Step Chromogenic Reaction.
abstract: The prevalently used immunoassays for fast screening of aftatoxins (AFs) usually cannot meet the requirement for simultaneous determination of total AFs (aflatoxin B1 + aflatoxin B2 + aflatoxin G1 + aflatoxin G2) due to the deficiency of highly group-specific antibodies. This paper describes a two-step chromogenic reaction based method to quantitatively detect total AFs in rice using colorimetric measurement without antibody. In the method, colorless AFs transform into green-colored indophenol products through the reaction with sodium hydroxide and 2,6-dibromoquinone-4-chloroimide (DBQC) successively, allowing selectively determining total AFs up to 3.9 μg/kg over other competitive mycotoxins under optimal conditions by a UV-vis spectrophotometer. In addition, the colorimetric measurement results of the rice samples agree well with that of a standard HPLC method, demonstrating the good reliability and applicability of the method. Uniquely, the method has potential for on-site detection of total AFs in rice when using a nylon membrane-based device.
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Bibai
authors.initials: B
authors.lastname: Du
authors.affiliation: Key Laboratory of Agro-Product Safety and Quality, Ministry of Agriculture, Institute of Quality Standards & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Xiaoou
authors.initials: X
authors.lastname: Su
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Kunhao
authors.initials: K
authors.lastname: Yang
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Long
authors.initials: L
authors.lastname: Pan
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Qingju
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Gong
authors.affiliation: Key Laboratory of Agro-Product Safety and Quality, Ministry of Agriculture, Institute of Quality Standards & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Peilong
authors.initials: P
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Jingkui
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences , Beijing 100049, China.|State Key Laboratory of Natural and Biomimetic Drugs, Peking University , Beijing 100191, China.
authors.forename: Yujian
authors.initials: Y
authors.lastname: He
mesh_terms: D000348:Aflatoxins / Q000032:analysis* / Q000737:chemistry; D003124:Colorimetry / Q000379:methods*; D007215:Indophenol / Q000031:analogs & derivatives / Q000138:chemical synthesis; D057230:Limit of Detection; D012275:Oryza / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry
chemical_list: D000348:Aflatoxins; D011809:Quinones; D007215:Indophenol; C039515:2,6-dibromoquinone 4-chlorimide; D012972:Sodium Hydroxide