Fluorescent and Magnetic Relaxation Switch Immunosensor for the Detecting Foodborne Pathogen Salmonella enterica in Water Samples
WANG Song-bai1, ZHANG Yan1, AN Wen-ting1, WEI Yan-li1, WANG Yu2*, SHUANG Shao-min1*
1. Department of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, China 2. Beijing Institute for Tropical Medicine; Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
Abstract：Fluoroimmunoassay based on quantum dots（QDs） and magnetic relaxation switch (MRS) immunoassay based on superparamagnetic nanoparticles（SMN） were constructed to detect Salmonella enterica（S. enterica） in water samples. In fluoroimmunoassay, magnetic beads was conjugated with S. enterica capture antibody （MB-Ab2） to enrich S. enterica from sample solution，then the QDs was conjugated with the S. enterica detection antibody (QDs-Ab1) to detect S. enterica based on sandwich immunoassay format. And the fluorescence intensity is positive related to the bacteria concentration of the sample. Results showed that the limit of detection (LOD) of this method was 102 cfu·mL-1 and analysis time was 2 h. In MRS assay, magnetic nanoparticle-antibody conjugate (MN-Ab1) can switch their dispersed and aggregated state in the presence of the target. This state of change can modulate the spin-spin relaxation time (T2) of the neighboring water molecule. The change in T2 (ΔT2) positively correlates with the amount of the target in the sample. Thus, ΔT2 can be used as a detection signal in MRS immunosensors. Results showed that LOD of MRS sensor for S. enterica was 103 cfu·mL-1 and analysis time was 0.5 h. Two methods were compared in terms of advantages and disadvantages in detecting S. enterica.
王松柏1，张 彦1，安文汀1，卫艳丽1，王 宇2*，双少敏1* . 量子点荧光免疫和磁弛豫时间传感检测沙门氏菌的研究 [J]. 光谱学与光谱分析, 2015, 35(11): 3105-3110.
WANG Song-bai1, ZHANG Yan1, AN Wen-ting1, WEI Yan-li1, WANG Yu2*, SHUANG Shao-min1* . Fluorescent and Magnetic Relaxation Switch Immunosensor for the Detecting Foodborne Pathogen Salmonella enterica in Water Samples. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(11): 3105-3110.
[1] Cossu A, Witkowsky R D, Levin R E. Food Control, 2014, 46: 475. [2] Galikowska E, Kunikowska D, Tokarska-Pietrzak, E et al. European Journal of Clinical Microbiology & Infectious Diseases, 2011, 30(9): 1067. [3] Urata M, Iwata R, Noda K, et al. Biotechnology Letters, 2009, 31(5): 737. [4] Sapountzi E A, Tragoulias S S, Kalogianni D P，et al. Analytica Chimica Acta, 2015, 864: 48. [5] Zhang C, Lou J, Tu W, et al. Analyst, 2015, 140(2): 506. [6] Perez J M, Josephson L, O’Loughlin T，et al. Nature Biotechnology, 2002, 20(8): 816. [7] Haun J B，Yoon T J，Lee H，et al. Wiley Interdisciplinary Reviews-Nanomedicine and Nanobiotechnology, 2010, 2: 291. [8] Shao H，Yoon T J，Liong M，et al. Beilstein Journal of Nanotechnology, 2010, 1: 142. [9] Haun J B, Devaraj N K, Hilderbrand S A，et al. Nature Nanotechnology, 2010, 5(9): 660. [10] Chen Y P, Zou M Q, Wang D N, et al. Biosensors & Bioelectronics, 2013, 43: 6. [11] Koh I, Hong R, Weissleder R, et al. Angewandte Chemie-International Edition, 2008, 47(22): 4119. [12] Ling Y, Pong T, Vassiliou C C, et al. Nature Biotechnology, 2011, 29(3): 273. [13] Liong M, Tassa C, Shaw S Y, et al. Advanced Materials, 2011, 23(26): H254. [14] Ma W, Chen W, Qiao R, et al. Biosensors & Bioelectronics, 2009, 25(1): 240. [15] Chen Y, Ren H L, Liu N, et al. Journal of Agricultural and Food Chemistry, 2010, 58(16): 8895. [16] Yao He, Hao Tinglu, Li Mansai, et al. Advanced Materials, 2008, 20: 3416. [17] Wuister S F, Swart I, Driel F，et al. Nano Letters, 2003, 3(4): 504.
