title: Adsorption kinetics of pesticide in soil assessed by optofluidics-based biosensing platform.
abstract: The adsorption of pesticides in soil is a key process that affects transport, degradation, mobility, and bioaccumulation of these substances. To obtain extensive knowledge regarding the adsorption processes of pesticides in the environment, the new green assay technologies for the rapid, sensitive, field-deployable, and accurate quantification of pesticides are required. In the present study, an evanescent wave-based optofluidics biosensing platform (EWOB) was developed by combining advanced photonics and microfluidics technology for the rapid sensitive immunodetection and adsorption kinetics assay of pesticides. The robustness, reusability, and accuracy of the EWOB allow an enhanced prediction of pesticide adsorption kinetics in soil. Using atrazine (ATZ) as the target model, we found that the adsorption kinetics in soil followed a pseudo-second-order kinetic model. EWOB was compared with liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method and yielded a good correlation coefficient (r(2)=0.9968). The underestimated results of LC-MS/MS resulted in a higher adsorption constant of ATZ in soil derived from LC-MS/MS than that of a biosensor. The proposed EWOB system provides a simple, green, and powerful tool to investigate the transport mechanism and fate of pesticide residues.
authors.affiliation: School of Environment and Natural Resources, Renmin University of China, Beijing, China. Electronic address: longf04@ruc.edu.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Long
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Zhu
authors.affiliation: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing, China.
authors.forename: Hanchang
authors.initials: H
authors.lastname: Shi
authors.affiliation: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing, China.
authors.forename: Jianwu
authors.initials: J
authors.lastname: Sheng
authors.affiliation: State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, Beijing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D000327:Adsorption; D001280:Atrazine / Q000737:chemistry*; D015374:Biosensing Techniques; D002853:Chromatography, Liquid; D007700:Kinetics; D010573:Pesticide Residues / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D010573:Pesticide Residues; D012987:Soil; D012989:Soil Pollutants; D001280:Atrazine
keywords: Adsorption kinetics; Atrazine; Biosensor; Fluorescence immunoassay; Optofluidics