中文摘要：

采用柠檬酸钠还原法合成了粒径为13 nm 的金纳米粒子,并在其表面修饰上谷胱甘肽（ GSH-AuNPs）。在一定的盐浓度范围内,谷胱甘肽能保护金纳米粒子免受盐诱导的聚集。当神经元素3（ Neuroge-nin3,ngn3）多肽片段存在时,在一定的盐浓度下,ngn3片段能够诱导GSH-AuNPs发生聚集,使金纳米粒子溶液由红色变成蓝色。以谷胱甘肽修饰的金纳米粒子为探针,建立了快速检测ngn3片段的比色方法。通过优化得到的最适实验条件为：ngn3与 GSH-AuNPs 的平衡反应时间10 min,缓冲液pH=6.0, NaCl 浓度100 mmol/L。在优化条件下,检测ngn3的线性范围为20~300μg/L,检出限（ LOD）为8μg/L。结果表明,本方法具有良好的选择性,可用于实际样品的检测。

英文摘要：

The 13 nm gold nanoparticles （ AuNPs ） were synthesized through the reduction of HAuCl4 by sodium citrate and the glutathione was assembled on the AuNPs. Under the experiment conditions, glutathione-modified AuNPs （ GSH-AuNPs ） with negative charge presented a wine red color owing to the electrostatic repulsion between nanoparticals. Upon the addition of neurogenin 3 （ ngn3 ） peptide, the aggregation of GSH-AuNPs was induced by ngn3 peptide under a certain concentration of salt. The color of AuNPs solution changed from red to blue as a function of the ngn3 peptide concentration. Thus, a rapid detection method for ngn3 peptide using GSH-AuNPs as colorimetric probe was established. The optimal experiment conditions were equilibrium time=10 min, pH=6. 0, CNaCl=100 mmol/L. Under the optimum conditions, the assay showed a linear response range of 20-300 μg/L for the peptide with a detection limit being 8 μg/L and exhibited excellent selectivity for ngn3 peptide.