应用球形和海胆状金混合SERS基底检测高环多环芳烃

合成了海胆状金银复合纳米材料,并与球形金纳米材料混合作为表面增强拉曼活性基底实现了对水中高环多环芳烃的痕量检测。对海胆状材料进行表征,粒径大小约为300~400 nm,表面有40~100nm明显的刺状凸起。与球形金溶胶混合后并优化pH值及混合比例等参数,产生了优于球形金溶胶2~3倍的增强效果。利用此增强基底检测了危害严重的高环多环芳烃污染物——芘(四环)、苯并蒽(四环)、苯并芘(五环),得到的光谱数据反映出混合SERS基底有良好的重复性和稳定性,对测得光谱进行特征峰归属分析,固体拉曼光谱与水溶液SERS光谱有确定的对应关系,并且在低浓度范围多环芳烃特征峰峰强与其水溶液浓度有良好的线性关系。经计算,芘(四环)、苯并蒽(四环)、苯并芘(五环)的检测限分别为0.44,2.92和1.64 nmol·L~(-1)。该研究的创新点为合成了海胆金纳米颗粒,与球形金溶胶混合后制成新型高效SERS检测基底;选用自制高效SERS基底,实现了高环PAHs痕量检测。结果表明,利用该方法制备的活性基底,可实现对水中高环多环芳烃的痕量检测,为检测水中高环多环芳烃提供了实验室依据。

Detection of High Molecular Weight Polycyclic Aromatic Hydrocarbons in Mixed Colloid Solution of Spherical Au and Urchin-Like Au-Ag Alloy with Surface-Enhanced Raman Scattering

In this paper ,Au nanosphere and Au‐Ag alloy nanourchin were prepared by reducing the chloroauric acid .The mixed colloid solutions of Au nanosphere and Au‐Ag alloy nanourchin were used as surface‐enhanced Raman scattering (SERS) sub‐strate to detect polycyclic aromatic hydrocarbons (PAHs) in aqueous solution .The size of Au‐Ag alloy nanourchin particle was about 300~400 nm and the thorn‐like bulge covered on it was about 40~100 nm .The mixed colloid solutions of Au nanosphere and Au‐Ag alloy nanourchin which were optimized pH values and other parameters presented a better enhancement than Au nanosphere .The enhancement effect was about three times that of Au nanosphere colloid solution .Three kinds of high molecular weight PAHs ,pyrene(4 rings) ,benzoanthracene(4 rings) and benzoa]pyrene(5 rings) ,were detected .The results showed that there were good linear relationships between Raman intensity and concentration in the low concentration range and the mixed SERS substrate had a good reproducibility and stability .Their limits of detection (LODs) were 0.44 ,2.92 and 1.64 nmol · L -1 ,respectively . The innovation of this paper was that the mixed colloid solutions of Au nanosphere and Au‐Ag alloy nanourchin are prepared as SERS substrate and the trace‐level high molecular weight PAHs are detected .The results show that the detection of trace‐level high molecular weight PAHs in aqueous can be realized using the mixed SERS substrate prepared in this study ,which proposed an in‐situ method for detecting the high molecular weight PAHs in aqueous .