Nanobiotechnology for health-care

Chip based plasmon-enhanced fluorescence sensor for highly-sensitive zearalenone analysis 
Yarynka D.V.1, Chegel V.I.2, Dubey I.Ya.1, Dubey L.V.1, Stepanenko Ye.Yu1, Brovko O.O.3, and Sergeyeva T.A.1
1 Institute of Molecular Biology and Genetics of the NAS of Ukraine. Zabolotnogo str. 150, Kyiv-03143, Ukraine.
E-mail: d.v.yarinka@imbg.org.ua
2 V.E. Lashkaryov Institute of Semiconductor Physics of the NAS of Ukraine, Prospect Nauky, 41, Kyiv- 03680, Ukraine.
3 Institute of Macromolecular Chemistry of the NAS of Ukraine. Kharkivske Shosse, 48, Kyiv-02160, Ukraine.

The highly-sensitive chip-based plasmon-enhanced fluorescence (PEF) sensor system for fast and robust zearalenone analysis in grain foods was developed. Thin molecularly imprinted polymer (MIP) films with embedded in situ-synthesized Ag nanoparticles (AgNPs) immobilized on the surface of glass slides were used as sensing chips for the proposed PEF-based sensor system. The MIP films were synthesized according to a dummy template-based approach with cyclododecyl-2,4­dihydroxybenzoate as a template molecule and ethyleneglycolmethacrylatephosphate as a functional monomer. AgNPs were in-situ synthesized using reduction of AgNO3 which was added to the monomer composition. Spherical AgNPs (30–70 nm in diameter) were formed in MIP films structure during the pre-heating step and further UV-initiated polymerization procedure on the surface of glass slides. To provide covalent immobilization of the MIP films, glass slides were treated with γ-methacryloxypropyltrimethoxysilane. Enhanced fluorescence of ZON selectively adsorbed on the surface of glass chips coated with thin MIP films was registered with the standard laboratory spectrofluorimeter. The transmission electron microscopy was used to investigate the morphology and size of AgNPs embedded in the MIP film structure. The influence of AgNO3 concentration on the PEF phenomenon was also investigated. The LOD of ZON sensor chips was 5 ng/mL, and the linear detection range was 5-25 ng/mL. The developed AgNPs-containing MIP-based PEF sensor chips were successfully used for the analysis of ZON contamination in spiked and naturally contaminated grain samples.
Financial support from National Academy of Sciences of Ukraine is gratefully acknowledged.