Multi-residue detection of pesticides using a sensitive immunochip assay based on nanogold enhancement.
This paper describes the development of a new multiplex immunoassay for simultaneous detection of seven pesticides (triazophos, methyl-parathion, fenpropathrin, carbofuran, thiacloprid, chlorothalonil, and carbendazim). Sixteen pairs of pesticide antibodies and antigens were screened for reactivity and cross-reaction. A microarray chip consisting of seven antigens immobilized on a nitrocellulose membrane was then constructed. Nanogold was employed for labeling and signal amplification to obtain a sensitive colorimetric immunoassay. The direct and indirect detection formats were further compared using primary antibody-gold and secondary antibody-gold conjugates as tracers. An integrated 7-plex immunochip assay based on the indirect model was established and optimized. The detection limits for the pesticides were 0.02-6.45 ng mL(-1), which meets detection requirements for pesticide residues. Naked-eye assessment showed the visual detection limits of the assay ranged from 1 to 100 ng mL(-1). Spiked recovery results demonstrated that the immunochip assay had potential for multi-analysis of pesticide residues in vegetables and fruits. The proposed microarray methodology is a flexible and versatile tool, which can be applied to other competitive multiplex immunoassays for small molecular compounds.
Institute of Pesticide and Environmental Toxicology, Zhejiang University, 310058 Hangzhou, China.
Meijing
M
Lan
Institute of Pesticide and Environmental Toxicology, Zhejiang University, 310058 Hangzhou, China. Electronic address: yirongguo@zju.edu.cn.
Yirong
Y
Guo
Institute of Pesticide and Environmental Toxicology, Zhejiang University, 310058 Hangzhou, China.
Ying
Y
Zhao
Institute of Pesticide and Environmental Toxicology, Zhejiang University, 310058 Hangzhou, China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, 311400 Fuyang, China.
Yihua
Y
Liu
Institute of Pesticide and Environmental Toxicology, Zhejiang University, 310058 Hangzhou, China.
Wenjun
W
Gui
Institute of Pesticide and Environmental Toxicology, Zhejiang University, 310058 Hangzhou, China.
Guonian
G
Zhu
D005638:Fruit / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D014675:Vegetables / Q000737:chemistry
D010573:Pesticide Residues; D006046:Gold
Gold nanoparticles; Immunoassay; Microarray; Multi-residue; Pesticides