基于金纳米粒子比色检测重金属铅离子

Colorimetric Assay Based on Gold Nanoparticles for Detection of Pb Ions

目的研究一种新的基于半胱氨酸修饰的金纳米粒子的检测重金属铅离子的方法。方法采用柠檬酸钠还原法合成粒径为13 nm的金纳米粒子,并用半胱氨酸进行修饰（Cys-Au NPs）。在Pb2＋诱导下,Cys能通过螯合配体结合作用捕获Pb2＋,导致Au NPs聚集,使Au NPs特征峰的位置和强度发生变化,且溶液颜色发生变化。结果该比色法的检测范围为0.02~5μmol/L,检出限为0.01μmol/L。通过对比Pb2＋与其他金属离子的紫外可见光谱,证明该方法特异性好。结论该比色法可用于Pb2＋的实际检测应用中。

To develop a simple and sensitive colorimetric detection method for Pb2 ＋ based on cysteine functionalized gold nanoparticles（Cys-Au NPs）. Au NPs with a particle size of 13 nm were synthesized using sodium citrate reduction method and then functionalized with cysteine. Cys-Au NPs could be induced to aggregate immediately in the presence of Pb2 ＋ through chelating ligand binding, which led to the colorimetric response of Au NPs, with changes in the position and strength of Au NPs characteristic peaks as well as the solution color. The experimental results indicated that a good linear relationship was found in the Pb2 ＋ concentration range between 0.02 μmol/L and 5 μmol/L, and the limit of detection（LOD） was 0.01 μmol/L. The selectivity of this method was confirmed by comparison with the UV/Vis spectra of other divalent metal ions. The colorimetric method could be used in the actual application of Pb2＋ detection.