单链DNA表面增强拉曼散射检测条件的优化

Optimization of surface enhanced Raman scattering detection conditionsfor single-stranded DNA

目的:研究不同检测条件对单链脱氧核糖核酸(Single-Stranded Deoxyribonucleic Acid,ssDNA)表面增强拉曼散射(Surface-Enhanced Raman Spectroscopy,SERS)检测结果的影响,以确定最佳的检测条件。方法:以单链DNA GO18(序列为AACCTTTGGTCGGGCAAGGTAGGTT(5′~3′))为例,探讨不同检测条件(银胶溶液浓缩倍数、激发功率及积分时间、装样方式、凝聚剂MgSO4用量等)对SERS检测结果的影响规律。在最佳检测条件下,对稳定性、重复性和检测限进行考察并对光谱图进行峰位归属。结果:确定适于单链DNA检测的最佳条件是:银胶溶液浓缩100倍,激发功率30%(60 mW),积分时间30 s,装样方式为1.0~0.8高纯度石英毛细管,MgSO4(10mM)的用量2.0 L。该条件下测定结果的稳定性高,重复性好,检测限为0.625M。结论:本研究优化了单链DNA的SERS检测条件,为进一步扩大和推动SERS技术在单链DNA检测中的应用提供方法基础。

Objective:Studying the optimal detection conditions of surface-enhanced Raman Spectroscopy(SERS)for single-stranded deoxyribonucleic Acid(ssDNA).Method:ssDNA GO18(AACCTTTGGTCGGGCAAGGTAGGTT(5′~3′))is used as an example to explore the influence of different detection conditions(concentration of silver sol,laser power and integration time,sample loading method,dosage of coagulant MgSO4)on the results of SERS detection.Under the optimal detection conditions,the stability,repeatability,and detection limit were investigated,and the peak positions of the spectra were assigned.Result:The best conditions for determining ssDNA were as follows:silver sol was concentrated 100 times,laser power was 30%(60 mW),integration time was 30 s,the sample was loaded in 1.0-0.8 high-purity quartz capillary and the amount of MgSO4(10mM)was 2.0L.The measurement results under these conditions have high stability and good repeatability,and the detection limit is 0.625M.Conclusion:This study optimized SERS detection conditions for ssDNA and provided a method basis for further expanding and promoting the application of SERS technology in the field.