title: A highly sensitive immunoassay for atrazine based on covalently linking the small molecule hapten to a urea-glutaraldehyde network on a polystyrene surface.
abstract: A new enzyme-linked immunosorbent assay (ELISA) for atrazine was developed based on covalent bonding of the small molecule hapten, 2-mercaptopropionic acid-4-ethylamino-6-isopropylamino-1,3,5-triazine (MPA-atrazine), to urea-glutaraldehyde (UGA)-treated microtiter plates. In this assay, the microtiter plate surface was treated with the UGA network to both introduce amino groups, which were used to cross-link with the hapten carboxylate groups, and efficiently prevent non-specific adsorption of antibodies, which successfully eliminated the time-consuming routine blocking step. Compared with HNO3-H2SO4-APTES-hapten coated ELISA (modified with a HNO3-H2SO4-APTES mixture and covalent-linked hapten) and conventional ELISA (coated with hapten-carrier protein conjugates), the novel ELISA format increased the sensitivity by approximately 3.5-fold and 7.5-fold, respectively, and saved 2.5h and 34h of coating hapten time, respectively. The method's 50% inhibition concentration for atrazine was 5.54ngmL-1, and the limit of detection was 0.16ngmL-1after optimization of reaction conditions. Furthermore, the ELISA was adapted for analysis of atrazine in corn, rice, and water samples, demonstrating recoveries of 90%-108%. Thus, the assay provides a convenient alternative to conventional, laborious immunoassays for routine supervision of residue detection in food and the environment.
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, China.
authors.forename: Na
authors.initials: N
authors.lastname: Sai
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, China.
authors.forename: Yuntang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, China.
authors.forename: Guanggui
authors.initials: G
authors.lastname: Yu
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, 300070 Tianjin, China. Electronic address: huangguowei@tmu.edu.cn.
authors.forename: Guowei
authors.initials: G
authors.lastname: Huang
mesh_terms: D001280:Atrazine / Q000032:analysis*; D004785:Environmental Pollutants / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005976:Glutaral / Q000737:chemistry; D006241:Haptens / Q000737:chemistry; D006540:Herbicides / Q000032:analysis*; D006801:Humans; D012275:Oryza / Q000737:chemistry*; D011137:Polystyrenes; D012016:Reference Values; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014508:Urea / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D006241:Haptens; D006540:Herbicides; D011137:Polystyrenes; D013438:Sulfhydryl Compounds; D014867:Water; D014508:Urea; C023884:thiolactic acid; D001280:Atrazine; D005976:Glutaral
keywords: Atrazine; Immunoassay; Small molecule hapten; Urea-glutaraldehyde