氧化石墨烯负载金纳米颗粒SERS活性基底的制备与研究

Preparation and Study of GO Decorated with Au Nanoparticles as SERS Active Substrate

本文采用湿化学方法制备具有表面增强拉曼散射活性的氧化石墨烯负载纳米金溶胶:通过以柠檬酸三钠为还原剂,在没有稳定剂、温和的液相反应条件下,同时还原氯金酸和深度氧化的石墨烯,原位制备氧化石墨烯负载金纳米颗粒复合物。利用紫外可见分光光度计、激光粒度分析仪、傅里叶变换红外吸收光谱仪、透射电子显微镜对所制得的氧化石墨烯负载金纳米颗粒复合物进行了表征和分析,并且采用拉曼光谱研究其作为增强试剂的性能。结果表明:所得溶胶在波长为540nm左右存在较强的吸收峰,粒径分布在50nm附近范围内;生成的金纳米粒子的大小及其分布受氯金酸用量的影响,并且粒径分布均匀,金纳米颗粒的平均尺寸为20nm,大量金纳米颗粒均匀地附着在氧化石墨烯的片层之间;氧化石墨烯的含氧官能团大幅降低,氧化石墨烯表面基团大部分被还原;以R6G为探针分子验证其拉曼增强效应,在浓度低至10nmol/L时依然具有较强的拉曼信号,增强因子达到2.4×10~5。所以高分散性、高稳定性的氧化石墨烯负载金颗粒溶胶,可作为SERS活性基底(增强试剂),用于快速检测。

In this paper,wet chemical method was carried out for preparing graphene oxide decorated Au nanoparticles as SERS active substrate:in the absence of stabilizers and mild liquid phase reaction condition,sodium citrate was as used an efficient reducing agent in situ reducing both chloroauric acid and the deep oxidation of graphene.The prepared GO decorated with Au nanoparticles composite was characterized and analyzed by UV-visible spectrometer,laser particle size analyzer,FTIR spectrometer,transmission electron microscopy(TEM),meanwhile,the performance of the SERS substrate was researched by Raman spectrometer.The results showed that:the colloid obtained a strong absorption peak is present at around 540 nm,the colloid particle size distribution in the range of 50 nm nearby;the size and distribution of Au nanoparticles affected by the dosage of gold chloride acid,and the average size of Au nanoparticles was 20 nm,numerous Au nanoparticles were uniformly attached between the graphene oxide sheets;the FT-IR data showed that most of oxygen-containing functional groups were significantly reduced in the graphene oxide.R6G was used asaprobe molecules to verify the Raman enhancement effect,at the concentration as low as 10nmol/L still has a strong Raman signal,the enhancement factor can be reached to 2.4×10~5.So the high dispersion,high stability GO@AuNPs colloidal suspention can be used as SERS active substrate(enhanced reagent)for rapid detection.