Gold(III) enhanced chemiluminescence immunoassay for detection of antibody against ApxIV of Actinobacillus pleuropneumoniae

We report, for the first time, a chemiluminescence immunoassay (CLIA) method based on AuCl4- -enhanced luminol chemiluminescence (CL) reaction for the highly sensitive detection of ApxIV antibody of Actinobacillus pleuropneumoniae (APP). The AuCl4-, which was the dissolution product of the gold nanoparticle-rabbit anti-pig IgG conjugate, served as an analyte in the CL reaction for the indirect measurement of antibody against ApxIV. The optimal condition of gold dissolution was composed of a 5.0 x 10(-2) M HCl, 1.5 x 10(-2) M NaCl, and 2.5 x 10(-4) M Br-2 solution. Under the optimal conditions, a good correlation between the relative CL photon counting and the dilution coefficient of serum was obtained in the dilution range of 1:160-1:40 000. Based on the analysis of clinical samples, the results indicated that CLIA had remarkable advantages in terms of reliability and practical use compared with indirect hemagglutination (IHA) and enzyme-linked immunosorbent assays (ELISA). The proposed method provided a new tool for the indirect determination of antibody against ApxIV in pig serum samples and showed great potential for numerous applications in immunoassays.

我们首次报道了一种基于AuCl₄⁻增强的鲁米诺化学发光（CL）反应的化学发光免疫分析（CLIA）方法，用于高灵敏度检测胸膜肺炎放线杆菌（APP）的ApxIV抗体。AuCl₄⁻是金纳米粒子 - 兔抗猪IgG偶联物的溶解产物，在CL反应中作为分析物用于间接测量抗ApxIV抗体。金溶解的最佳条件是由5.0×10⁻² M HCl、1.5×10⁻² M NaCl和2.5×10⁻⁴ M Br₂溶液组成。在最佳条件下，在1∶160 - 1∶40000的血清稀释范围内，相对化学发光光子计数与血清稀释系数之间获得了良好的相关性。基于临床样本分析，结果表明与间接血凝试验（IHA）和酶联免疫吸附测定（ELISA）相比，CLIA在可靠性和实际应用方面具有显著优势。所提出的方法为间接测定猪血清样本中的抗ApxIV抗体提供了一种新工具，并在免疫分析的众多应用中显示出巨大潜力。