Toxins 2018, 10(7), 291; https://doi.org/10.3390/toxins10070291
Label-Free Optical Detection of Mycotoxins Using Specific Aptamers Immobilized on Gold Nanostructures
Ali Ghanim Al-Rubaye 1,2,*
, Alexei Nabok 1, Gaelle Catanante 3, Jean-Louis Marty 3, Eszter Takács 4 and András Székács 4
, Alexei Nabok 1, Gaelle Catanante 3, Jean-Louis Marty 3, Eszter Takács 4 and András Székács 4
1
Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB, UK
2
Basra Technical Institute, Southern Technical University, 61002 Basra, Iraq
3
Department of Biochemistry and Molecular Biology, University of Perpignan, 66100 Perpignan, France
4
Agro-Environmental Research Institute, NARIC, 1011-1239 Budapest, Hungary
*
Author to whom correspondence should be addressed.
Received: 26 June 2018 / Revised: 12 July 2018 / Accepted: 13 July 2018 / Published: 16 July 2018
(This article belongs to the Special Issue Advanced Sensors for Toxins)
Abstract
This work focuses on the development of the novel label-free optical apta-sensors for detection of mycotoxins. A highly sensitive analytical method of total internal reflection ellipsometry (TIRE) combined with Localized Surface Plasmon Resonance (LSPR) phenomenon in nano-structured gold films was exploited here for the first time for detection of aflatoxin B1 and M1 in direct assay with specific aptamers immobilized on the surface of gold. The achieved detection of low molecular weight molecules, such as aflatoxin B1 and M1, in a wide range of concentrations from 100 ng/mL down to 0.01 ng/mL is remarkable for the LSPR method. The study of binding kinetics of aflatoxin molecules to their respective aptamers using dynamic TIRE measurements yielded the values of affinity constants in the range of 10−8–10−7 mol, which is characteristic for highly specific aptamer/target interactions similar to that for monoclonal antibodies. The effect of aptamers’ DNA chain length on their binding characteristics was analyzed. View Full-TextKeywords:
optical label-free biosensor; mycotoxins; aptamer; LSPR; gold nanostructures; total internal reflection ellipsometery
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Ghanim Al-Rubaye, A.; Nabok, A.; Catanante, G.; Marty, J.-L.; Takács, E.; Székács, A. Label-Free Optical Detection of Mycotoxins Using Specific Aptamers Immobilized on Gold Nanostructures. Toxins 2018, 10, 291.
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