Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (16): 1748-1754.DOI: 10.6023/A12030074 Previous Articles    

Full Papers


蒋治良, 姚东梅, 李芳, 梁爱惠   

  1. 药用资源化学与药物分子工程教育部重点实验室 珍稀濒危动植物生态与环境保护省部共建教育部重点实验室 广西师范大学 桂林 541004
  • 投稿日期:2012-03-30 发布日期:2012-05-26
  • 通讯作者: 蒋治良, 梁爱惠
  • 基金资助:

    项目受国家自然科学基金(Nos. 21165005, 21075023)和药用资源化学与药物分子工程教育部重点实验室基金(No. CMEMR2011-10)资助.

Resonance Scattering Assay for Trace Human Chorionic Gonadotrophin Using Gold-platinum Nanoalloy Immunoprobe as Catalyst

Jiang Zhiliang, Yao Dongmei, Li Fang, Liang Aihui   

  1. Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Education Ministry;Key Laboratory of Ecology of Rare and Endangered Species and Environmental Conservation of Education Ministry,Guangxi Normal University, Guilin 541004
  • Received:2012-03-30 Published:2012-05-26
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21165005, 21075023) and the Fund of Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Guangxi Normal University), Ministry of Education of China (No. CMEMR2011-10).

In the presence of sodium citrate as stabilizer, a gold-platinum nanoalloy (GP) in the mole ratio of 49∶1 was prepared by using NaBH4 as a reducing agent. The rabbit anti-human chorionic gonadotrophin antibody (RhCG) was labeled by the GP to obtain a stable immune GP probe (GP-RhCG) for the human chorionic gonadotrophin (hCG). In a pH 5.8 NaH2PO4-citric acid buffer solution and in the presence of KCl, the GP-RhCG probe was aggregated un-specifically to big particles that exhibited a resonance scattering (RS) peak at 590 nm. When the hCG was added, the GP-RhCG probe combined specifically with the hCG to form a dispersed GP-RhCG-hCG immunocomplex that resulted in the RS intensity decreasing at 590 nm. The decreased RS intensity (ΔI590 nm) is linear with hCG concentration in the range of 6.67—86.7 ng/mL, with a detection limit of 3.7 ng/mL hCG. The immunocomplex exhibited a strong catalytic effect on the slow Cu2O particle reaction of glucose-Cu(II), and the particles appeared a RS peak at 610 nm. When the hCG concentration increased in the immune reaction system, the immunocomplex concentration increased, and the catalytic product of Cu2O particles increased, which caused the enhancement of RS intensity at 610 nm. The increased intensity (ΔI610 nm) is linear with the hCG concentration in the range of 3.33—133 ng/mL, with a detection limit of 1.7 ng/mL hCG. In addition, the influence of foreign substances on the determination of hCG was examined. The results show that 150 times of L-aspartic acid, urea, BSA, glycine, Ca(II) and Zn(II), 50 times of L-lysine and L-cysteine, 30 times of IgG and IgA, 40 times of IgM did not interfered with the determination of 80 ng/mL hCG. This indicates that this method has good selectivity. The hCG content in the serum sample was analyzed by the GP RS method and GP-catalytic RS method, the results are agreement with those of the chemiluminescence experiments. Both RS methods are of some advantages including low-cost, simplicity, rapidity, high sensitivity and selectivity.

Key words: human chorionic gonadotrophin, gold-platinum nanoalloy, immunonanocatalysis, resonance scattering assay