基于溴化氢诱导下纳米金氧化刻蚀比色法检测六价铬  

Colorimetric Detection of Cr(Ⅵ) Based on the Oxidation Etching of Gold Nanoparticles Induced by Hydrogen Bromide

作　　者：贵莉莉[1] GUI Li-li(Xinxiang Vocational and Technical College,Xinxiang 453000,Chin)

机构地区：[1]新乡职业技术学院,河南新乡453000

出　　处：《化学试剂》2017年第12期1315-1318,1337,共5页Chemical Reagents

摘　　要：设计了一种基于纳米金被六价铬氧化刻蚀的高灵敏度、高专一性的比色传感器来检测六价铬。当溴化氢存在时,由能斯特方程得到Cr6+/Cr3+的标准电势高于Au+/Au的标准电势。因此,当六价铬存在时,纳米金被刻蚀成小粒径的纳米粒子,导致在520 nm处的吸光度不断降低,650 nm处的吸光度则不断增大。六价铬的浓度在0.1~100μmol/L范围内,对数值与吸光度变化值呈良好的线性关系,线性方程为y=0.083 32x+0.082 86,相关系数R为0.99,检出限为0.06μmol/L,其他金属离子几乎不存在干扰。本方法用于自来水样品中六价铬的测定,实验结果令人满意。A highly sensitive and specific colorimetric sensor for Cr（Ⅵ） detection based on the oxidation etching of gold nanoparticles by Cr（Ⅵ） was designed. In the presence of hydrogen bromide,based on the Nernst equation,the electron potential of Cr（Ⅵ）/Cr（Ⅲ） is higher than that of Au（I）/Au（0）.Thus,the gold nanoparticles are etched to nanoparticles with smaller particle size,which leads to the gradual decrease of the absorbance value at 520 nm,and the gradual increase of the absorbance value at 650 nm.There is a good linear relationship between the absorbance change and the logarithm of the Cr（Ⅵ） concentrations in the range of 0. 1 ~ 100 μmol/L.Its regression equation is y = 0. 083 32 x＋0. 082 86,and the correlation coefficient is 0. 99,with a low detection limit of 0. 06 μmol/L,and there is almost no interference from other metal ions.The method is applied to the detection of Cr（Ⅵ） in tap water with a satisfactory result.

关 键 词：纳米金 溴化氢 六价铬 氧化刻蚀 比色 

分 类 号：O65[理学—分析化学]