title: Attomole sensitivity of staphylococcal enterotoxin B detection using an aptamer-modified surface-enhanced Raman scattering probe.
abstract: In this report, we present a new homogeneous detection method for staphylococcal enterotoxin B (SEB) utilizing core-shell-structured iron-gold magnetic nanoparticles and a gold nanorod surface-enhanced Raman scattering (SERS) probe in solution. Peptide ligand (aptamer) functionalized magnetic gold nanorod particles were used as scavengers for target SEB. After the SEB molecules were separated from the matrix, the sandwich assay procedure was tested by gold nanorod particles that act as SERS probes. The binding constant between SEB and peptide-nanoparticle complex was determined as 8.0 × 10(7) M(-1). The correlation between the SEB concentration and SERS signal was found to be linear within the range of 2.5 fM to 3.2 nM. The limit of detection for the homogeneous assay was determined as 224 aM (ca. 2697 SEB molecules/20 μL sample volume). Also, gold-coated surfaces were used as capture substrates and performances of the two methods were compared. Furthermore, the developed method was evaluated for investigating the SEB specificity on bovine serum albumin (BSA) and avidin and detecting SEB in artificially contaminated milk, blood, and urine.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey.
authors.forename: Erhan
authors.initials: E
authors.lastname: Temur
authors.forename: Adem
authors.initials: A
authors.lastname: Zengin
authors.forename: İsmail Hakkı
authors.initials: İH
authors.lastname: Boyacı
authors.forename: Fahriye Ceyda
authors.initials: FC
authors.lastname: Dudak
authors.forename: Hilal
authors.initials: H
authors.lastname: Torul
authors.forename: Uğur
authors.initials: U
authors.lastname: Tamer
mesh_terms: D000595:Amino Acid Sequence; D052158:Aptamers, Peptide / Q000737:chemistry* / Q000378:metabolism; D004768:Enterotoxins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D017433:Protein Structure, Secondary; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D052158:Aptamers, Peptide; D004768:Enterotoxins; C031818:enterotoxin B, staphylococcal