化学学报 ›› 2011, Vol. 69 ›› Issue (06): 713-718. 上一篇    下一篇

研究论文

适体修饰纳米金催化-共振散射光谱测定凝血酶

蒋彩娜1,2,梁爱惠1,蒋治良*,1   

  1. (1广西师范大学环境与资源学院 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 桂林 541004)
    (2桂林医学院 桂林 541004)
  • 投稿日期:2010-06-02 修回日期:2010-10-12 发布日期:2010-11-25
  • 通讯作者: 蒋治良 E-mail:zljiang@mailbox.gxnu.edu.cn
  • 基金资助:

    国家自然科学基金项目

Resonance Scattering Spectral Detection of Trace Thrombin Using Aptamer Modified Nanogold as Probe and Nanocatalyst

Jiang Caina1,2 Liang Aihui1 Jiang Zhiliang*,1   

  1. (1 Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, School of Environment and Resource Sciences, Guangxi Normal University, Guilin 541004 )
    (2 Guilin Medical University, Guilin 541004)
  • Received:2010-06-02 Revised:2010-10-12 Published:2010-11-25

用核酸适体修饰纳米金制备了识别凝血酶(TB)的适体修饰纳米金(AptAu)共振散射光谱探针. 在pH 7.40 的Na2HPO4-NaH2PO4缓冲溶液中及NaCl, KCl存在下, AptAu探针中的适配体特异识别凝血酶, 生成稳定的G-四分体和大粒径的纳米金聚集体. 经微孔滤膜过滤后, 纳米金聚集体被分离, 以滤液中未反应的AptAu作催化晶种, 在20.0 μg/mL HAuCl4-5.01 mmol/L HCl-1.83 mg/mL CTMAB-50.1 μg/mL VC条件下, 催化维生素C (VC)还原HAuCl4生成较大粒径的金颗粒, 体系在600 nm处有一共振散射峰. 随着凝血酶浓度的增大, 滤液中AptAu浓度降低, 催化作用减弱, 600 nm处的共振散射峰降低, 其降低值ΔI600 nm与凝血酶浓度在6.40×10-3~0.150 U/mL范围内存在良好线性关系, 回归方程为ΔI=1.26×103C+1.50, 相关系数为0.999, 检出限为1.30×10-3 U/mL. 该法用于定量分析人血浆中凝血酶, 结果满意.

关键词: 凝血酶, 适体, 纳米金催化, 共振散射光谱法

An aptamer nanoprobe (AptAu) for thrombin was prepared using the nanogold labeled aptamer. In pH 7.4 Na2HPO4-NaH2PO4 buffer solution and in the presence of NaCl and KCl, the analyte of thrombin reacted with AptAu to form stable G-quartet and release nanogold particles that aggregated to big clusters. After filtration by microporous filter membrane, the big clusters were removed and filtrated solution containing AptAu was obtained. That exhibited catalytic effect on the slow gold particle reaction between HAuCl4 and VC at 60 ℃. There is a resonance scattering peak at 600 nm. With the increasing concentration of thrombin, the AptAu content in the filtrated solution decreased, and the resonance scattering intensity at 600 nm decreased. The decreased RS intensity is linear to thrombin concentration in the range from 6.40×10-3 U/mL to 0.150 U/mL, with a regression equation of ΔI=1.26×103C+1.50 and a detection limit of 1.30×10-3 U/mL. The method was used for quantitative analysis of thrombin in human plasma with satisfactory results.

Key words: thrombin, aptamer, nanogold catalysis, resonance scattering spectral assay