多环芳烃的表面增强拉曼光谱探测与分析

首次实现了以参数优化的金溶胶为表面增强拉曼散射(SERS)活性基底探测水中痕量的多环芳烃。采用化学还原法制备不同颗粒大小的金溶胶，实验确定了632.8 nm激发光下的最优金纳米颗粒的平均粒径为(32±3) nm，并以此金溶胶为基底，探索pH值对多环芳烃增强效果的影响，发现pH=13效果最佳，与pH=6相比谱线绝对强度提高约20倍。以粒径为(32±3) nm，pH=13的金溶胶为活性基底对不同浓度萘、菲、芘溶液进行了SERS光谱探测，探测到的最低浓度分别为20，4和4 nmol·L-1，特征峰强与浓度呈线性关系，线性拟合相关系数均在0.985以上，三者混合溶液的SERS光谱可清晰分辨出各自的特征峰。结果表明，该实验所采用的SERS活性基底灵敏度较高，具有广阔的应用前景。

Detection and Analysis of Polycyclic Aromatic Hydrocarbons Using Surface-Enhanced Raman Spectroscopy

In the present paper,the gold colloid with parameters optimized was used as surface-enhanced Raman scattering(SERS) active substrate to realize the trace detection of polycyclic aromatic hydrocarbons(PAHs) in water for the first time.Gold colloids with different size were prepared using chemical reduction method,and the optimum size selected at 632.8 nm excitation wavelength by experiment is(32±3) nm.The influence of pH value on the enhancement of PAHs was researched,and the optimal pH value is 13.Spectral intensity increased by approximately 20-fold compared with pH 6.The SERS spectra of naphthalene,phenanthrene and pyrene aqueous solutions were detected by the optimum gold colloid,and the minimum concentrations obtained were 20,4 and 4nmol·L-1,respectively.There was a linear relationship between peak intensity and concentration,and the linear regression correlation coefficients were all above 0.985.For the mixture,the authors could distinguish each PAH easily for their own characteristic peaks.The experimental results show that such active substrate has a very high sensitivity as well as good application prospect.