无线磁弹性免疫传感法测定水中痕量镉

Determination of Trace Cadmium in Water by Wireless Magnetoelastic Immunosensor

基于抗原抗体特异性结合使镉附着在免疫传感器表面导致磁弹片共振频率降低的原理,建立了应用磁弹性免疫传感法测定水中痕量镉的方法。其共振频率变化对应于磁弹性片表面附着物的质量变化。研究了聚乙烯亚胺用量、戊二醛用量、反应时间等因素对测定的影响。在最佳条件下,测定镉的线性范围为0.90～10.0μg/L,检出限为为0.42μg/L。应用本方法测定了水样中的镉,测定结果与双硫腙比色法一致,回收率为96.5%～103.6%。

A new method for the determination of Cd in the water with a wireless magnetoelastic immunosensor was introduced. In the method, the specific binding of antigen with the antibody made precipitation adhere to the surface of the immunosensor and resulted in a decrease in the resonance frequency of the magnetoelastic foil. The shift of the resonance frequency was related to the concentration of Cd. The influence of some factors such as polyethylene imine dosage, glutaraldehyde dosage and reaction time on the determination was discussed. At the optimized conditions, the linear range for the determination of Cd was in the range of 0. 90-10. 0μg/L, with the detection limit of 0. 42 μg/L. The proposed method was applied successfully to the determination of Cd in water samples with the recoveries of 96. 5% -03.6%. The determination results are basically consistent with that of dithizone colorimetric method.