کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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870218 | 909856 | 2007 | 9 صفحه PDF | دانلود رایگان |
A surface plasmon resonance (SPR) based immunosensor has been developed for the monitoring of environmentally persistent pollutants like DDT, its metabolites and analogues in real water samples. A reusable immunosurface is provided via the covalent attachment of the analyte derivative to a self-assembled alkanethiol monolayer formed onto the SPR gold-thin layer. The regeneration of the sensor surface allowed the performance of 270 assay cycles within an analysis time of 20 min for each assay cycle. Immunoassays based on a binding inhibition format were performed by using two monoclonal antibodies (MAbs) with different selectivity. Low limits of detection (LODs), in the sub-nanogram per litre range, were attained for DDT-selective (15 ng L−1) and DDT group-selective immunoassays (31 ng L−1). Both assays were carried out in spiked river water samples without significant effect of the matrix. SPR measurements were validated using gas-chromatography–mass spectrometry. The comparison between methods was in good agreement showing an excellent correlation coefficient (r2 = 0.995). The SPR analysis of DDT proved to be three times more sensitive than colorimetric ELISAs without the need of labelling and a much lower time of response. Our SPR biosensor portable platform (β-SPR) is already commercialised by the company SENSIA, S.L. (Spain).
Journal: Biosensors and Bioelectronics - Volume 22, Issue 7, 15 February 2007, Pages 1410–1418