TY - JOUR
T1 - Electrochemical biosensing of pesticide residues based on affinity biocomposite platforms
AU - Zacco, E.
AU - Galve, R.
AU - Marco, M. P.
AU - Alegret, S.
AU - Pividori, M. I.
PY - 2007/3/15
Y1 - 2007/3/15
N2 - A novel and very sensitive electrochemical immunosensing strategy for the detection of atrazine based on affinity biocomposite transducers is presented. Firstly, the graphite-epoxy composite transducer was bulk-modified with different universal affinity biomolecules, such as avidin and Protein A. Two strategies for the immobilization of the anti-atrazine antibodies on both biocomposite transducers were evaluated: 'wet-affinity' and 'dry-assisted affinity' immobilization. Finally, the performance of a novel anti-atrazine immunocomposite bulk-modified with anti-atrazine antibodies was also evaluated. The better immobilization performance of the anti-atrazine antibodies was achieved by 'dry-assisted affinity' immobilization on Protein A (2%) graphite-epoxy biocomposite (ProtA(2%)-GEB) as a transducer. The immunological reaction for the detection of atrazine performed on the ProtA(2%)-GEB biosensors is based on a direct competitive assay using atrazine-HRP tracer as the enzymatic label. The electrochemical detection is thus achieved through a suitable substrate and a mediator for the enzyme HRP. This novel strategy was successfully evaluated using spiked orange juice samples. The detection limit for atrazine in orange juices using the competitive electrochemical immunosensing assay was found to be 6 × 10-3 μg L-1 (0.03 nmol L-1) thus this biosensing method accomplishes by far the LODs required for the European Community directives for potable water and food samples (0.1 μg L-1). This strategy offers great promise for rapid, simple, cost effective, and on-site biosensing of biological, food, and environmental samples. © 2006 Elsevier B.V. All rights reserved.
AB - A novel and very sensitive electrochemical immunosensing strategy for the detection of atrazine based on affinity biocomposite transducers is presented. Firstly, the graphite-epoxy composite transducer was bulk-modified with different universal affinity biomolecules, such as avidin and Protein A. Two strategies for the immobilization of the anti-atrazine antibodies on both biocomposite transducers were evaluated: 'wet-affinity' and 'dry-assisted affinity' immobilization. Finally, the performance of a novel anti-atrazine immunocomposite bulk-modified with anti-atrazine antibodies was also evaluated. The better immobilization performance of the anti-atrazine antibodies was achieved by 'dry-assisted affinity' immobilization on Protein A (2%) graphite-epoxy biocomposite (ProtA(2%)-GEB) as a transducer. The immunological reaction for the detection of atrazine performed on the ProtA(2%)-GEB biosensors is based on a direct competitive assay using atrazine-HRP tracer as the enzymatic label. The electrochemical detection is thus achieved through a suitable substrate and a mediator for the enzyme HRP. This novel strategy was successfully evaluated using spiked orange juice samples. The detection limit for atrazine in orange juices using the competitive electrochemical immunosensing assay was found to be 6 × 10-3 μg L-1 (0.03 nmol L-1) thus this biosensing method accomplishes by far the LODs required for the European Community directives for potable water and food samples (0.1 μg L-1). This strategy offers great promise for rapid, simple, cost effective, and on-site biosensing of biological, food, and environmental samples. © 2006 Elsevier B.V. All rights reserved.
KW - Atrazine
KW - Avidin
KW - Electrochemical biosensing
KW - Graphite-epoxy biocomposite
KW - Immunoassay
KW - Protein A
U2 - 10.1016/j.bios.2006.07.037
DO - 10.1016/j.bios.2006.07.037
M3 - Article
SN - 0956-5663
VL - 22
SP - 1707
EP - 1715
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
IS - 8
ER -