Determination of human IgG by solid substrate-room temperature phosphorescence immunoassay

作者：Liu JM^*; Xu HH; Li PP; Chen BH; Li LD; Gao JP

来源：Analytical Letters, 2004, 37(14): 2991-3003.

DOI：10.1081/AL-200035867

• human IgG
• luminescent nanoparticle as labeling reagent
• solid substrate-room temperature phosphorescence immunoassay
• fluorescein isothiocyanate.

Silicon dioxide nanoparticle containing fluorescein isothiocyanate (FITC-SiO2) with the particle size of 20 nm was synthesized by solgel method. It can emit strong and stable solid substrate-room temperature phosphorescence (SS-RTP) signal on the substrate of polyamide membrane. It was found in the research that the specific reaction between goat-antihuman IgG antibody labeled with FITC-SiO2 and human IgG (immunoglobulin) can be carried on the polyamide membrane quantitatively, the antigen-anti body conjugate retained good phosphorescence properties, and the signal of phosphorescence was enhanced after the immunoassay reaction. Based on the facts above, a new method of solid substrate-room temperature phosphorescence immunoassay (SS-RTP-IA) to determine human IgG was established. The linear range of this method is 0.080-20.0pg human IgG spot(-1) (sample volume 0.40 mul spot(-1), and the corresponding concentration range of human IgG is 0.20-50.00 ng ml(-1)). The regression equation of the working curve is DeltaIp = 19.97 + 15.92 m (IgG) (pg spot(-1)), n = 6, correlation coefficient is 0.9997. The detection limit of this method calculated by 3 Sb/k is 0.015 pg spot(-1). Compared with the immunoassay using FITC to label goat-antihuman IgG, the sensitivity was obviously improved. For the sample containing 0.20 (ng ml(-1)) and 50.0 (ng ml(-1)) human IgG, with a sample volume of 0.40 mul, the relative standard deviation (RSD) is 3.4% and 4.1% (n = 11), respectively. This indicated very good repeatability.

• 出版日期2004-11
• 单位闽南师范大学; 清华大学