多巴胺修饰自组装金电极作为生物传感器测定核酸  

Determination of DNA by using a self-assemblied dopamine-modified Au electrode as biosensor

作　　者：干宁[1] 葛从辛[1] 

机构地区：[1]宁波大学理学院化学系

出　　处：《分析试验室》2006年第2期55-58,共4页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金(20075023);配位化学国家重点实验室开放基金资助

摘　　要：采用衍生化接枝法制备了多巴胺（DA）-半胱氨（Cys）自组装修饰金电极（DA-Cys-SAM）,研究了其电化学性质.在pH 7.5的Tris-HCl底液中,采用循环伏安法测定其Epa=218 mV,Epc=120 mV,△E=98 mV,ipa/ipc≈1,电极反应准可逆.采用示差脉冲法（DPV）研究发现DA氧化峰电流随DNA质量浓度提高而显著变大且峰电位不变,峰电流的增加值与DNA质量浓度在1×10^-7～1.2×10^-5g/mL范围内成正比,检出限达5×10^-8g/mL,相对标准偏差为3.2%（n=8,5×10^-7g/mL DNA）.该电极对DNA测定具有特异性,对实际样品进行了测定.A dopamine-cysteine monolayer membrane modified gold electrode was prepared by using self-assembly tech- nique and chemical derivative method. In the buffer of 0.1 mol/L Tris-HCl of pH7.5, the electrode shows one pair of redox peaks Epa = 218 mV, Epc = 120 mV. △E = 98 mV and Ipa/Ipc≈1, indicating the electrode reaction is quasireversible. The electron transfer coefficient （ α） was 0.44 and rate constant （Ks） is 0.03 s^-1. The average surface coverage of DA was 2.3 × 10^-10 mol/cm^2 . The oxidation peak current of DA is linear with DNA concentration in the range of 1 × 10^-7 - 1.2 × 10^-5 mom/L determined by differential pulse voltammetry （DPV）. The detection limit is 5 × 10^-8 g/mL and relative standard deviation is 3.4% （n = 8, 5 × 10^-7 g/mL DNA）. Moreover, the electrode has specific response for the determination of DNA while not for RNA.

关 键 词：自组装 多巴胺(DA) 核酸 化学修饰电极 示差脉冲法(DPV) 

分 类 号：O657.1[理学—分析化学]