基于表面增强拉曼光谱的肝癌血清检测方法研究

Study on the detection method of liver cancer serum spectrum based on surface enhanced Raman spectroscopy

测量了基于金溶胶和银溶胶基底的肝癌血清的SERS光谱,比较两种金属溶胶对肝癌血清SERS增强效果。为了得到灵敏度更高的表面增强拉曼光谱,探究了银溶胶与血清比例为0∶1、1∶2、1∶3、1∶1、2∶1、3∶1的肝癌血清SERS光谱,寻找合适的银溶胶与血清配比。测定了以80nm、50nm、30nm三种不同粒径银溶胶为基底的肝癌血清SERS光谱,比较不同粒径的银溶胶对SERS光谱的影响。结果显示以金溶胶和银溶胶为基底的血清SERS谱,都能够反映血清中蛋白质主链、侧链的结构,但是基于金溶胶的血清SERS光谱对蛋白质二级结构及脂类和糖的测定效果较差,银溶胶的SERS增强效果优于金溶胶。当血清与银纳米配比为1∶1时,SERS增强效果最强,其他配比所测得SERS特征峰强度减弱。以粒径50nm的银溶胶为基底的血清SERS明显增强,增强活性优于粒径80nm的银溶胶和粒径30nm的银溶胶。结果表明在肝癌血清的检测中,选择粒径50nm左右的银纳米溶胶作为基底,且血清与银溶胶配比1∶1时,可以得到最佳的肝癌血清SERS光谱。

In this paper, the liver cancer serum SERS based on gold sol and silver sol substrate are measured, and the enhancement effects of two kinds of metal colloids on liver cancer serum SERS are compared. In order to obtain surface enhanced Raman spectra of higher sensitivity, exploring liver cancer serum SERS of the silver sol and serum ratio of 0 ： 1, 1 ： 2, 1 ： 3, 1 ： 1, 2 ： 1 and 3 ： 1, to find the suitable ratio of silver sol and serum. The liver cancer serum SERS with three different sizes of silver sol substrate of 80nm, 50nm and 30nm are measured, and the influ- ences of silver sol with different sizes on SERS spectra are compared. Results reveal that serum SERS spectra of the gold sol and silver sol substrates based can reflect the serum protein main chain and side chain structure. However, the serum SERS based on gold sol has poor effect on the determination of protein secondary structure, lipid and sugar. And SERS enhancement effect of silver sol is better than that of gold sol. When serum and silver sol ratio is 1 ： 1, the en- hancement effect is the strongest, while the strength of SERS peaks decreased with other ratios. The serum SERS, which is based on the silver sol with a particle size of 50nm, is obviously enhanced, and the silver sol enhanced activi- ty is better than that of silver sol with particle size 80nm and silver sol with 30nm. The results show that the best liver cancer serum SERS spectrum can be obtained when a silver nanometer solution with diameter of 50nm is selected and the serum ratio and silver sol is 1 ： 1.