title: An impedimetric immunosensor based on interdigitated microelectrodes (IDmicroE) for the determination of atrazine residues in food samples.
abstract: A novel impedimetric immunosensor for atrazine detection has been developed. The immunosensor is based on an array of interdigitated micro-electrodes (IDmicroE) and immunoreagents specifically developed to detect this pesticide. Immunochemical determination of atrazine is possible without the use of any label. An atrazine-haptenized protein was covalently immobilized on the surface of the interdigitated mu-electrodes area (interdigits space) previously activated with (3-glycidoxypropyl)trimethoxysilane. Before, the gold electrodes were blocked using N-acetylcysteamine to prevent non-specific adsorptions. All biofunctionalization steps were characterized by chemical affinity methods and impedance spectroscopy. Immunosensors measures are made by exposing the sensor to solutions containing a mixture of the analyte and the specific antibody. With this configuration, the immunosensor detects atrazine with a limit of detection of 0.04 microg L(-1) without the use of any label. The potential of the immunosensor to analyze pesticide residues in complex sample matrices, such as red wine, has been evaluated. The results shown that after solid-phase extraction atrazine can be determined in this type of sample with a limit of detection of 0.19 microg L(-1), far below the Maximum Residue Level (MRL) established by EC for residues of this herbicide in wine.
authors.affiliation: Applied Molecular Receptors Group (AMRg(1)), CSIC, CIBER of Bioengineering, Biomaterials and Nanomedicine, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Ramón-Azcón
authors.forename: Enrique
authors.initials: E
authors.lastname: Valera
authors.forename: Angel
authors.initials: A
authors.lastname: Rodríguez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Barranco
authors.forename: Begoña
authors.initials: B
authors.lastname: Alfaro
authors.forename: Francisco
authors.initials: F
authors.lastname: Sanchez-Baeza
authors.forename: M-Pilar
authors.initials: MP
authors.lastname: Marco
mesh_terms: D001280:Atrazine / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D005504:Food Analysis; D006540:Herbicides / Q000032:analysis*; D007118:Immunoassay / Q000379:methods*; D008839:Microelectrodes; D010573:Pesticide Residues / Q000032:analysis*; D014920:Wine / Q000032:analysis
chemical_list: D006540:Herbicides; D010573:Pesticide Residues; D001280:Atrazine