title: Ultrasensitive SERS detection of Bacillus thuringiensis special gene based on Au@Ag NRs and magnetic beads.
abstract: Highly sensitive and selective detection of specific DNA sequences is of great importance in clinical diagnosis, environmental and food monitoring, but it still remains challenges to develop a facile method for real sample detection in aqueous solution. Here, a simple and recyclable surface enhanced Raman scattering (SERS) sensor was constructed for Bacillus thuringiensis (Bt) special gene fragment detection by Fe3O4magnetic beads (MBs) and Au-Ag core-shell nanorods (Au@Ag NRs). A hairpin DNA with sulfhydryl and biotin was attached to Au@Ag NRs as indicator, and MBs with streptavidin (SA) were acted as the capture probe. On the basis of the biotin-SA specific interaction, target sequences were first hybridized with the hairpin DNA and exposed the biotin. Subsequently, the Au@Ag NRs were captured by the streptavidin modified MBs, which reduced the suspended NRs and led to the change of Raman intensity. Under the optimal conditions, the SERS intensity revealed a good linearity with Bt transgene fragment ranging from 0.1pM to 1nM with a detection limit of 0.14pM (S/N=3). To demonstrate the specificity of the strategy, the single-base mismatch in DNA was discussed in the SERS assay. The results showed that the sensitivity and accuracy of the proposed method was acceptable in DNA detection, revealing a great potential in special gene detection.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Long
authors.initials: L
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Wenmin
authors.initials: W
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Pan
authors.initials: P
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Food Science and Technology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China. Electronic address: hyhan@mail.hzau.edu.cn.
authors.forename: Heyou
authors.initials: H
authors.lastname: Han
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics* / Q000302:isolation & purification; D015374:Biosensing Techniques / Q000379:methods; D004269:DNA, Bacterial / Q000235:genetics*; D006046:Gold / Q000737:chemistry*; D059346:Magnets / Q000737:chemistry; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D019076:Transgenes
chemical_list: D004269:DNA, Bacterial; D012834:Silver; D006046:Gold
keywords: Au-Ag core-shell nanorods; Bacillus thuringiensis transgene; Magnetic beads; Surface Raman enhanced scatting