title: A rapid method for detection of genetically modified organisms based on magnetic separation and surface-enhanced Raman scattering.
abstract: In this study, a new method combining magnetic separation (MS) and surface-enhanced Raman scattering (SERS) was developed to detect genetically modified organisms (GMOs). An oligonucleotide probe which is specific for 35 S DNA target was immobilized onto gold coated magnetic nanospheres to form oligonucleotide-coated nanoparticles. A self assembled monolayer was formed on gold nanorods using 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) and the second probe of the 35 S DNA target was immobilized on the activated nanorod surfaces. Probes on the nanoparticles were hybridized with the target oligonucleotide. Optimization parameters for hybridization were investigated by high performance liquid chromatography. Optimum hybridization parameters were determined as: 4 μM probe concentration, 20 min immobilization time, 30 min hybridization time, 55 °C hybridization temperature, 750 mM buffer salt concentration and pH: 7.4. Quantification of the target concentration was performed via SERS spectra of DTNB on the nanorods. The correlation between the target concentration and the SERS signal was found to be linear within the range of 25-100 nM. The analyses were performed with only one hybridization step in 40 min. Real sample analysis was conducted using Bt-176 maize sample. The results showed that the developed MS-SERS assay is capable of detecting GMOs in a rapid and selective manner.
authors: Department of Food Engineering, Faculty of Engineering, Hacettepe University, Beytepe, Ankara, 06800, Turkey.
authors: Burcu
authors: B
authors: Guven
authors: İsmail Hakkı
authors: İH
authors: Boyacı
authors: Ugur
authors: U
authors: Tamer
authors: Pınar
authors: P
authors: Çalık
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004228:Dithionitrobenzoic Acid / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D049329:Nanostructures / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods; D015345:Oligonucleotide Probes / Q000737:chemistry / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013696:Temperature; D003313:Zea mays / Q000235:genetics*
chemical_list: D015345:Oligonucleotide Probes; D006046:Gold; D004247:DNA; D004228:Dithionitrobenzoic Acid