巯基丁二胺铜单层修饰金电极上HIV-p24抗原的电化学免疫检测

Immunoassay of HIV-p24 Antigen at the Gold Electrode Madified with Monolayer of Cupric Mercapto-Butadiamine

制备了用巯基丁二胺铜(CuL)修饰的金电极并用作HIV-p24抗原蛋白(简称p24)免疫检测的化学传感器。CuL通过单层自组装固定在金电极表面,其覆盖率为1.02×10-11mol.cm-2,在含有1.0 mmol.L-1过氧化氢并在pH 6.2的磷酸盐缓冲溶液中,制备的校正曲线的线性范围为0.5-150μg.L-1p24对相应的伏安响应,方法的检出限为0.2μg.L-1。在10μg.L-1p24浓度水平作精密度试验,得RSD值为3.5%,于试样中分别加入5,15,20及30μg.L-1p24进行回收率试验,所得结果在98%-102%之间。此方法毋需另加电子传递媒介体。应用此方法于临床血清分析,所得结果与放射性免疫法的结果一致,且所得RSD值均小于0.3%。

The gold electrode was modified with cupric mercapto-butadiamine （abbreviated as CuL） and used as a chemical sensor in the immuno-assay of the antigen HIV-p24. The sensor was self-assembled with a monolayer of CuL, giving a surface coverage of 1.02× 10^-11 mol · cm^-2. Calibration curve was prepared and a linearity in the range of 0. 5 ng to 150 μg per L of HIV-p24 against the voltammetric response, in a phosphate buffer solution of pH 6. 2, and containing 1.0 mmol · L^-1 of H2O2 was obtained. The detection limit found was 0. 2 μg · L^-1. Precision was tested with a same electrode at the concentration level of 10 μg ·L^-1 of HIV-p24, and the RSD obtained was 3.5%. Recovery was tested by addition of HIV-p24 at known concentrations of 5,15,20 and 30 μg · L^-1 , and the values of recovery found were in the range of 98%- 102%. The addition of electron transfer mediator to the test solution was not necessary in in proposed method. In the application of this method to clinical analysis of serum samples, the results obtained were in consistency with those obtained by the radio-immunoassay, and the RSD＇s （n=7） obtained were less than 0. 3%.