title: Nano-magnetic immunosensor based on staphylococcus protein a and the amplification effect of HRP-conjugated phage antibody.
abstract: In this research, super-paramagnetic Fe3O4 nanoparticles (magnetic particles) were coated with Staphylococcus protein A (SPA) and coupled with polyclonal antibody (pcAb) to construct magnetic capturing probes, and HRP-conjugated phage antibody was then used as specific detecting probe to design a labeled immunosensor for trace detection of Staphylococcus aureus enterotoxin B (SEB). The linear detection range of the sensor was 0.008~125 µg/L, the regression equation was Y = 0.487X + 1.2 (R = 0.996, N = 15, p < 0.0001), the limit of detection (LOD) was 0.008 µg/L, and the limit of quantification (LOQ) was 0.008 µg/L. HRP-conjugated phage antibody, SPA and magnetic particles can enhance the sensitivity 4-fold, 3-fold and 2.6-fold higher, respectively. Compared with conventional double-antibody sandwich ELISA, the detection sensitivity of the sensor was 31-fold higher resulting from the integrated amplifying effect. The immunosensor integrates the unique advantages of SPA-oriented antibody as magnetic capturing probe, HRP-conjugated phage antibody as detecting probe, magnetic separation immunoassay technique, and several other advanced techniques, so it achieves high sensitivity, specificity and interference-resistance. It is proven to be well suited for analysis of trace SEB in various environmental samples with high recovery rate and reproducibility.
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. mxh0511@sohu.com.
authors: Xihui
authors: X
authors: Mu
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. billzytong@126.com.
authors: Zhaoyang
authors: Z
authors: Tong
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. qibin_huang@126.com.
authors: Qibin
authors: Q
authors: Huang
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. lbfhyjy@sohu.com.
authors: Bing
authors: B
authors: Liu
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. liuzhw07@lzu.edu.cn.
authors: Zhiwei
authors: Z
authors: Liu
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. hlq70@163.com.
authors: Lanqun
authors: L
authors: Hao
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. zjp337@126.com.
authors: Jinping
authors: J
authors: Zhang
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. g.ch.chuan@263.net.
authors: Chuan
authors: C
authors: Gao
authors: Research Institute of Chemical Defence, State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. wfwei2012@163.com.
authors: Fenwei
authors: F
authors: Wang
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D001435:Bacteriophages / Q000737:chemistry; D015374:Biosensing Techniques; D004768:Enterotoxins / Q000276:immunology / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D013205:Staphylococcal Protein A / Q000737:chemistry; D013211:Staphylococcus aureus / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000906:Antibodies; D004768:Enterotoxins; D058185:Magnetite Nanoparticles; D013205:Staphylococcal Protein A; C031818:enterotoxin B, staphylococcal; D006046:Gold