Colloidal SERS Substrate for the Ultrasensitive Detection of Biotinylated Antibodies Based on Near-Field Gradient within the Gap of Au Nanoparticle Dimers
JOURNAL OF PHYSICAL CHEMISTRY C
Authors: Mercadal, Pablo A.; Encina, Ezequiel R.; Coronado, Eduardo A.
Abstract
Surface-enhanced Raman spectroscopy (SERS) has demonstrated to be a powerful technique for the ultrasensitive detection of different types of analytes and particularly biomolecules, with the rational design of SERS substrates being one of the most relevant issues for the development of effective detection protocols. In this work, a colloidal SERS substrate consisting of a pair of Au nanorods linked by the molecular bridge biotin/streptavidin/biotin has been obtained and employed for the detection of picomolar quantities of the biotinylated antibodies gliadin IgG and Ara h1 IgG, which is of great interest in food science. As a consequence of the bioconjugation strategy implemented, the SERS substrate, that is, the Au nanorod dimer, presents the advantage of combining in a single nanostructure the capabilities for both direct and indirect detection of the biotinylated antibodies. Furthermore, the experimental results are supported by detailed electrodynamics simulations which takes into account not only the gradient of the near-field enhancements within the hot spot but also the volume occupied by the respective biomolecules. The SERS substrate presented here could be straightforwardly employed for the ultrasensitive detection of other biotinylated biomolecules.
Variation in cold tolerance in F-6 durum wheat [Triticum turgidum (L.) Tell. convar. durum (Desf.) Mackey] RILs and the relationships of cold tolerance with some quality parameters and genetic markers
JOURNAL OF AGRICULTURAL SCIENCE
Authors: Taskin, Belgin Gocmen; Ozbek, Ozlem; San, Sibel Keskin; Eser, Vehbi; Nachit, Miloudi Mikael; Kaya, Zeki
Abstract
Low temperature is one of the critical factors for determining agricultural production. Therefore, the main objective was to develop the durum wheat lines, which are tolerant to cold particularly in Central Anatolia. The recombinant inbred lines (RILs) (141) derived from F-6 progeny of durum wheat, developed from Kunduru-1149 (female parent) and Cham-1 (male parent) cross, were characterized in terms of their cold tolerance both in the field and under controlled (in growth chamber) conditions. A 0-9 scale was used for the visual evaluation of cold damage under field conditions, and a quantitative measure of photochemical efficiency (Fv/Fm = variable fluorescence/maximum fluorescence) method was used for the evaluation of cold damage under controlled conditions. Seventeen RILs displayed the scores within the range of 1-2.5 in 0-9 scale evaluation, while 41 RILs showed the scores equal to or higher than 0.70 approaching to optimal (similar to 0.83) in Fv/Fm evaluation. Some quality parameters tested and some gliadin fragments and random amplified polymorphic DNA loci showed meaningful correlations with the data of 0-9 scale and Fv/Fm ratios from lower to the medium level. The RILs considered as cold resistant; might have the potential to be used as parental lines to develop cold-resistant durum wheat varieties in the future durum wheat-breeding programmes.