茎环结构DNA循环放大技术测定水样中的痕量银离子  

Determination of Ag^+ in the water samples by the amplification technique with the cyclic hybridiazation of stem-loop structure DNA

作　　者：杜平[1] DU Ping(College of Chemistry, Binzhou University, Binzhou, Shandong 256600, Chin)

机构地区：[1]滨州学院化学化工学院,山东滨州256600

出　　处：《化学研究与应用》2018年第5期666-671,共6页Chemical Research and Application

基　　金：山东省高校科技发展计划项目(2012GGX10206)资助;滨州市科技发展计划项目(2013ZC1603)资助;滨州学院科研基金项目(BZXYG1515)资助

摘　　要：利用茎环结构DNA的循环杂交放大作用和碱基C与Ag^+之间的稳定结构,设计了一种高灵敏性的表面增强拉曼生物传感器用于水样中Ag^+的检测。首先制备了携带有大量拉曼信号分子的纳米金生物条码作为拉曼信号探针。然后通过酰胺键将捕获DNA固载在磁珠表面上,利用C-Ag^+-C形成的稳定结构和链式循环杂交反应放大技术,将含有大量拉曼信号DNA分子的纳米金颗粒通过生物素和链霉亲和素的特异性结合到磁珠上,最后通过SERS技术实现了溶液中Ag^+的检测。最佳实验条件下,当固定磁珠捕获DNA浓度为1.0×10^(-7)M,Tris-HCl缓冲溶液为pH7.4,37℃下杂交反应2.5 h后,Ag^+的浓度与拉曼信号强度呈良好的线性关系,测定线性范围为1.0×10^(-7)~1.0×10^(-12)M,检测限1.0×10^(-12)M(S/N=3)。该传感器用于海产品中Ag^+的测定,测定值与ICP-AES的测定值基本一致。A high sensitive Surface Enhance Raman biosensor for the detection of silver in water samples was designed by the cyclic hybridization amplification reaction on stem-loop structure DNA and by the stability of C and Ag＋. Firstly, nano-Au bio-bar-code was prepared with lots of Raman signal DNA, then capture DNA was imnlobilized on magnetic beadsby anfido bonds, the nano-Au particles linked a lot of signal DNA were combined specificly on the magnetic beads by the C-Ag＋ -C and the amplification of the chain-lype hybridization. The optimunl experiment conditions were also investigated. As the concentration of capture DNA is 1.0 ×10^-7M,the hybridization reaction was acted for 2. 5 h at the temperature of 37 oC in pH7.4 Tris-HC1 buffer solution,the SERS re- sults for the detection of Ag＋was showed that the concentration of Ag＋and the Raman intensity has good linear relationship, the line- ar range was 1.0×l0^-7 - 1.0×l0^-12M,the detection linfit was 1.0×10^-12 M（S/N=3） o The biosensor was applied to determination of Ag＋in the wastewater samples. And the determination results were consisitent with those obtained by ICP-AES.

关 键 词：茎环结构DNA 杂交循环放大表面增强拉曼技术 AG^+ 

分 类 号：O657.3[理学—分析化学]