An Ultrasensitive Simultaneous Immunoassay Based on Arsenic and Mercury Ions Labeled SiO2@Au Nanoparticle Probes
10.3724/SP.J.1096.2014.40048
- VernacularTitle:基于砷和汞离子标记 SiO2@Au 纳米探针的超敏多元免疫分析方法研究
- Author:
Tianhua LI
;
Ning GAN
;
Dazhen WU
;
Haijuan JIN
;
Yuting CAO
;
Qianli JIANG
- Publication Type:Journal Article
- Keywords:
Simultaneous immunoassay;
Tumor markers;
Arsenic and mercury ions labeled SiO2 Au nanoprobes;
Hydride generation-atomic fluorescence
- From:
Chinese Journal of Analytical Chemistry
2014;(6):817-823
- CountryChina
- Language:Chinese
-
Abstract:
An ultrasensitive immunoassay was developed based on As3+ and Hg2+ labeled SiO2 @ Au nanoparticles signal tags and hydride generation-atomic fluorescence spectrometry (HG-AFS) for the detection of carcinoembryonic antigen(CEA) and carbohydrate antigen 19-9 (CA 19-9) respectively. Firstly, amino SiO2@ Au NPs were synthesized for selective absorption of As3+ and Hg2+ ions respectively. Subsequently,the secondary antibody (Ab2) of CEA and CA 19-9 was respectively labeled on As3+ or Hg2+-SiO2 @ Au NPs to prepare the corresponding signal tags for CEA and CA 19-9. Based on the sandwich immunoassay scheme, the tags, two antigen and corresponding first antibodies were bio-conjugated on the bottom of 96-well plate at room temperature to form the immunocomplex. After it was dissolved in alkali solution, As3+ and Hg2+ ions were released in solution and detected by HG-AFS, which concentration was proportional with logarithms of CEA and CA 19-9. The reaction conditions were optimized and the tags were characterized. This assay was based on determination of the concentration of As3+ and Hg2+ for quantization of the corresponding CEA and CA 19-9 antigen. The assay showed a wide linear range from 0. 001 to 100. 0 μg / L for CEA and 0. 01-80 U/ mL for CA 19-9, and a lower detection limit of 0. 5 ng / L and 0. 005 U/ mL respectively. This proposed method was used in real serums samples, the results were consistence with that by ELISA. The immunoassay showed three orders of magnitude of sensitivity lower than that of ELISA, which provides a promising simultaneous immunoassay for the early diagnosis of cancer .
