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A Research Of Immune Magnetic Nanoparticles Separation Coupled SPR Sensor For Ultrasensitive Detection Of Deltamethrin

Posted on:2015-07-10Degree:MasterType:Thesis
Country:ChinaCandidate:L LiFull Text:PDF
GTID:2181330470452283Subject:Nutrition and Food Hygiene
Abstract/Summary:PDF Full Text Request
In this paper, a new approach that combines two-channel SPR sensor technology with immune magnetic nanoparticles (MNPs) is developed for directly detecting of deltamethrin in soybean. The MNPs conjugated with antibodies specific to antigen serves as both "labels" for enhancing refractive index change due to the capture of target analyte, and "vehicles" for the rapid delivery of analyte from a sample solution to the sensor surface. At the same time, SPR direct format and gas chromatography analysis consulting the national standards of deltamethrin detection were respectively conducted for detection of deltamethrin in soybean to demonstrate the amplification effect of MNPs with accuracy, repeatability and sensitivity. The main study content and results were summarized as follows:1. The preparation and characterization of immune MNPsCarboxyl-coated Fe3O4MNPs was produced using one-step chemical coprecipitation method with fulvic acid solution providing carboxyl groups. Carboxyl-coated MNPs can be easily functionalized by antibodies using amino coupling method, and the relevant concentration of antibodies and MNPs were optimized, which the0.27mg/mL deltamethrin monoclonal antbibodies could be fully band with the0.45mg/mL MNPs.2. MNPs enhanced SPR response to detect deltamethrin was achieved by the deltamethrin coated immune MNPs to band with the chitosan electrostatic self-assembly SPR sensor membrane, which could induce enough SPR response to detect deltamethrin. The equation of linear regression of this method was Y=24.08+270.08X (R2=0.9852), and the range of relative standard deviation (RSD) was1.69-8.09%. The lowest detection concentration was0.01ng/mL, and the limit of detection (LOD) was2.55pg/mL(S/N=3). Soybean as real sample was taken to conduct standard addition recovery study, and the range of the recovery was96.94%-104.4%(RSD2.18%~13.72%).3. SPR direct format for deltamethrin detection was achieved by deltamethrin monoclonal antbibodies to band with3-Mercaptopropionic acid functioned SPR sensor membrane, and then capture the deltamethrin to measure the relevant SPR respose. The equation of linear regression of this method was Y=25.31+0.21X (R2=0.9844), and the range of RSD was 3.22%-9.69%. The lowest detection concentration was50ng/mL, and LOD was27.3ng/mL(S/N=3). Soybean as real sample was taken to conduct standard addition recovery study, and the range of the recovery was76.6%-92.7%(RSD3.99%-6.7%).4. According to the national standard of GC-ECD format for deltamethrin detection (GB/T5009.146-2008), double chromatographic column and electronic catcher detector were used to take the qualitative and quantitative measurement. The equation of linear regression was Y=3.46X+112.02(R2=0.9893). The lowest detection concentration was100ng/mL. Soybean as real sample was taken to conduct standard addition recovery study, and the range of the recovery was82.89%-88.74%(RSD5.13%-9.65%).The SPR response of MNPs enhanced format was significantly higher than the SPR response of SPR direct format and GC-ECD format for deltamethrin detection, and the lowest detection concentration was respectively0.01ng/mL,50ng/mL and100ng/mL, and the lowest detection concentration of MNPs enhanced SPR format reduced respectively four and five orders of magnitudes comparing with the others.
Keywords/Search Tags:SPR, magnetic nanoparticles, delthamethrin, chitosan, pesticide residue detection
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