基于Ag^+对C-C错配识别和Ru(phen)_2(dppx)^(2+)的核酸分子“光开关”特性的银离子光学传感器  

An Optical Sensor for Ag^+ Based on Its Recognition of C-C Mismatched Base Pair and Nucleic Acid Molecule “Light Switch”Property of Ru(phen)_2(7,8-dimethyl-dipyridophenazine)^(2+)

作　　者：肖志友[1,2] 郭晓婷[2] 凌连生[2] 

机构地区：[1]凯里学院化学与材料工程学院,贵州凯里556011 [2]中山大学化学与化学工程学院,广东广州510275

出　　处：《分析测试学报》2013年第9期1117-1121,共5页Journal of Instrumental Analysis

基　　金：贵州省科学技术基金资助项目(黔科合J字[2013]2263号);国家自然科学基金资助项目(20975116)

摘　　要：以含错配碱基胞嘧啶的自互补寡聚核苷酸序列(Oligo-1,5'-TACATACTATACTATCTA-3')作为Ag+识别序列,以核酸分子"光开关"Ru(phen)2(dppx)2+(phen=1,10-phenanthroline,dppx=7,8-dimethyldipyridophenazine)作发光探针,建立了一种简单、灵敏的Ag+定量分析方法。以150 nmol/L Oligo-1,2.0μmol/L Ru(phen)2(dppx)2+及120 mmol/L NaNO3在pH 7.5的PBS缓冲溶液中反应30 min作为最佳实验条件,Ag+在10.0~120.0 nmol/L范围内与溶液的发光强度呈良好的线性关系,相关系数(r)为0.995 7,检出限(3δ/Slope)为8.1 nmol/L。方法具有较好的选择性,用于实际样品测定,结果满意。A simple and sensitive optical sensor for Ag＋was developed based on its recognition of C-C mismatched base pair and nucleic acid molecule ＂light switch＂ property of Ru（phen）2（7,8-dimethyldipyridophenazine）2＋.A self-complementary oligonucleotide containing cytosine-cytosine mismatched base pair,5-TACATACTATACTATCTA-3-（oligo-1）,was designed as the sequence for sensing of silver ion.In the absence of silver ion,the hybridization between the oligo-1 strands would not occur because of the existence of cytosine- cytosine mismatched base pair.However,after adding the silver ion,hybridization occurred between the two oligo-1 strands because of the formation of cytosine-Ag＋-cytosine base pair,the formed double-helix DNA prevented the luminescence of nucleic acid molecule ＂light switch＂ Ru（phen）2（7,8-dimethyldipyridophenazine）2＋ from the quenching of water.As a result,the luminescence of Ru（phen）2（dppx）2＋ increased dramatically.Based upon this mechanism,a simple and sensitive method for the detection of silver ion was established.Different factors including concentrations of oligo-1,Ru（phen）2（dppx）2＋,NaNO3,pH value and incubation time were investigated.The optimum conditions were as followins：Oligo-1：150 nmol/L,Ru（phen）2（dppx）2＋：2.0 μmol/L,NaNO3：120 mmol/L,buffer：20 mmol/L pH 7.5 PBS,incubation time：30 min.Under the optimal conditions,the luminescence intensity was proportional to concentration of Ag＋over the range of 10.0-120.0 nmol/L,with a correlation coefficient（r） of 0.995 7.The limit of detection（3δ/Slope） was 8.1 nmol/L.With a good selectivity,the method was applied in the determination of Ag＋in practical samples with satisfactory results.

关 键 词：DNA 核酸分子“光开关” 银离子 光学传感器 

分 类 号：O657.3[理学—分析化学] O612[理学—化学]