Indirect competitive immunoassay for the detection of fungicide Thiabendazole in whole orange samples by Surface Plasmon Resonance.
A highly sensitive and specific SPR-based competitive immunoassay for the detection of Thiabendazole (TBZ) has been developed. An indirect format where a TBZ-protein conjugate is immobilized onto gold surfaces has been selected. Under the optimal conditions, a LOD of 0.67 nM (0.13 μg L(-1)) and an IC(50) of 3.2 nM (0.64 μg L(-1)) have been achieved which are comparable to the values obtained by conventional ELISA. Analysis of real samples has been attempted by first evaluating the influence of complex matrix samples coming from whole oranges and secondly measuring samples containing TBZ previously evaluated by chromatographic methods. A methanolic extraction procedure followed by a simple dilution in assay buffer has proven to be sufficient to measure orange samples using the developed immunoassay with an excellent recovery percentage. The sensitivity and the feasibility of measuring whole orange samples demonstrate the effectiveness and robustness of the SPR biosensor, which can be useful for the determination of TBZ in food at concentrations below the Maximum Residue Levels (MRLs) established by the European legislation.
Nanobiosensors and Bioanalytical Applications Group, Research Centre in Nanoscience and Nanotechnology CIN2, CSIC & CIBER-BBN, 08193 Bellaterra, Barcelona, Spain. mcarmen.estevez@cin2.es
M-Carmen
MC
Estevez
Jose
J
Belenguer
Silvia
S
Gomez-Montes
Javier
J
Miralles
Alfonso M
AM
Escuela
Angel
A
Montoya
Laura M
LM
Lechuga
D015374:Biosensing Techniques / Q000379:methods; D032084:Citrus sinensis / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis*; D005659:Fungicides, Industrial / Q000032:analysis*; D007118:Immunoassay / Q000379:methods; D010573:Pesticide Residues / Q000032:analysis; D020349:Surface Plasmon Resonance; D013827:Thiabendazole / Q000032:analysis* / Q000276:immunology
D005659:Fungicides, Industrial; D010573:Pesticide Residues; D013827:Thiabendazole