TY - JOUR
T1 - Conductimetric immunosensor for atrazine detection based on antibodies labelled with gold nanoparticles
AU - Valera, Enrique
AU - Ramón-Azcón, Javier
AU - Sanchez, F. J.
AU - Marco, M. P.
AU - Rodríguez, Ángel
N1 - Funding Information:
This work has been supported by the Ministry of Science and Technology (Contract numbers TEC2004-0121-E and TEC2004-06854-C03-03/MIC) and by the European Community (IST-2003-508774). The MNT group is a consolidated Grup de Recerca de la Generalitat de Catalunya since the year 2001 (expedient 00329).The AMR group is a consolidated Grup de Recerca de la Generalitat de Catalunya and has support from the Departament d’Universitats, Recerca i Societat de la Informació la Generalitat de Catalunya (expedient 2005SGR 00207).
PY - 2008/8/28
Y1 - 2008/8/28
N2 - A novel conductimetric immunosensor for atrazine detection has been designed and developed. This immunosensor is mainly based on antibodies labelled with gold nanoparticles. Additionally, the immunosensor consists of an array of two coplanar non-passivated interdigitated metallic μ-electrodes (IDμE) and immunoreagents specifically developed to detect this pesticide. The chemical recognition layer was covalent immobilized on the interdigital space. Immunochemical detection of the concentration of atrazine is achieved by a competitive reaction that occurs before the inclusion of the labelled antibodies. It is shown that the gold nanoparticles provide an amplification of the conductive signal and hence makes possible to detect atrazine by means of simple DC measurements. The conductimetric immunosensor and its biofunctionalization steps have been characterized by chemical affinity methods and impedance spectroscopy. This work describes the immunosensor structure, fabrication, physico-chemical and analytical characterization, and the immunosensor response using conductivity measurements. The immunosensor developed detects atrazine with limits of detection in the order of 0.1-1 μg L-1, far below the maximum residue level (MRL) (100 μg L-1) established by European Union (EU) for residues of this herbicide in the wine. Although in this paper the competitive reaction occurs in buffer, an initial study of the wine matrix effect is also described.
AB - A novel conductimetric immunosensor for atrazine detection has been designed and developed. This immunosensor is mainly based on antibodies labelled with gold nanoparticles. Additionally, the immunosensor consists of an array of two coplanar non-passivated interdigitated metallic μ-electrodes (IDμE) and immunoreagents specifically developed to detect this pesticide. The chemical recognition layer was covalent immobilized on the interdigital space. Immunochemical detection of the concentration of atrazine is achieved by a competitive reaction that occurs before the inclusion of the labelled antibodies. It is shown that the gold nanoparticles provide an amplification of the conductive signal and hence makes possible to detect atrazine by means of simple DC measurements. The conductimetric immunosensor and its biofunctionalization steps have been characterized by chemical affinity methods and impedance spectroscopy. This work describes the immunosensor structure, fabrication, physico-chemical and analytical characterization, and the immunosensor response using conductivity measurements. The immunosensor developed detects atrazine with limits of detection in the order of 0.1-1 μg L-1, far below the maximum residue level (MRL) (100 μg L-1) established by European Union (EU) for residues of this herbicide in the wine. Although in this paper the competitive reaction occurs in buffer, an initial study of the wine matrix effect is also described.
KW - Antibodies
KW - Atrazine
KW - Conductive measurements
KW - Food safety
KW - Gold nanoparticles
KW - Immunosensor
KW - Impedance spectroscopy
KW - Interdigitated μ-electrodes
KW - Wine matrix effect
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U2 - 10.1016/j.snb.2008.04.023
DO - 10.1016/j.snb.2008.04.023
M3 - Article
AN - SCOPUS:49749100475
VL - 134
SP - 95
EP - 103
JO - Sensors and Actuators, B: Chemical
JF - Sensors and Actuators, B: Chemical
SN - 0925-4005
IS - 1
ER -