RESUMEN
A new magnetic affinity immunoassay (MAIA) strategy based on enzyme-labeled phage displayed antibody was developed. The assay consisted of a sandwich format in which immobilized polyclonal antibody (pcAb) on magnetic microparticle was used for capture probe, and enzyme-labeled phage displayed antibody for specific detection probe to increase enzyme amount and enhance detection signal. By the proposed method,β-bungarotoxin (β-BGT) was successfully detected. A linear relationship between absorbance value and the concentration of β-BGT in the range of 0. 016-62. 5 μg / L was obtained. The linear regression equation was Y=0. 641X+1. 355 (R =0. 9925, n = 13, p<0. 0001) with a detection limit of 0. 016 μg / L. In comparison with the traditional ELISA, this method gave a 10-fold better sensitivity in β-BGT detection. This strategy also gave a 4-fold better sensitivity comparing with the MAIA based on enzyme labeled monoclonal antibody (mcAb). Due to low detection limit, acceptable reproducibility and high specificity, this method holds great promise in toxin trace detection.
RESUMEN
A new method for O-ethyl S-[2-( diisopropylamino) ethyl] methylphosphonothiolate ( VX) , sarin detection and its kinetic analysis based on piezoresistive microcantilever aptasensor was developed, where VX, sarin aptamers were immobilized on the microcantilever surface by biotin-avidin binding system. A linear relationship between the response voltage and the concentration of VX in the range of 2-60μg/L was obtained. The linear regression equation was △Ue=0. 886C-1. 039 (n=5, R=0. 984, p<0. 001) and the detection limit was 2μg/L ( S/N≥3 ) . A linear relationship between the response voltage and the concentration of sarin in the range of 10-60 μg/L was obtained, the linear regression equation was △Ue=0. 716C-2. 304 ( n=5, R=0 . 996 , p<0 . 001 ) and the detection limit was 10 μg/L ( S/N≥3 ) . The sensor showed no response for O-butyl methylphosphonochloridate, a structural analog of VX and sarin, which indicated high specificity and good anti-interference ability. On this basis, a reaction kinetic model based on receptor-ligand binding and the relationship with output voltage change was established. Response voltage (△Ue ) and response time( t0 ) were obtained from the fitting equation on different concentrations of VX, sarin fitted well with the measured values.
RESUMEN
Objective To study the effects of perinatal exposure of diphenylchloroarsine chloride(DA)on the livability and reproductive function of F1 generation rats.Methods The pregnant rats were treated with DA by gavage at 0(solvent control),0.63(low dose),0.94(medium dose),1.89(high dose)mg/(kg?day)from day 6 of pregnancy to day 15 of lactation.The general condition,the change of body weight and abnormity of main organs of the F0 pregnant rats and F1 young rats were observed,and the livability and abnormity of reproductive function of F1 young rats were examined.Results The results indicated that compared with the negative control,the increasing amounts of the body weights of the F0 maternal rats and the livability of F1 young rats aged 4 day significantly decreased at 0.94 mg/kg and 1.89 mg/kg,the livability in lactation period obviously reduced at 1.89 mg/kg,and the rate of absorbed fetus in F1 pregnant rats increased at 1.89 and 0.94 mg/kg.Conclusion DA exposure may have an adverse effect on livability and reproductive function of the F1 offspring when the dosage is no fewer than 0.94 mg/kg.