摘要
在 ｐＨ＜６．２的 ＮａＣｌ介质中，Ｃｅ（Ⅲ）受 ２５４．０ ｎｍ紫外光激发所产生的 ３５０．０ ｎｍ荧光因 Ｃｅ（Ⅲ）的各种阳离子型体与小牛胸腺（ｃｔ）ＤＮＡ上的磷酸根发生静电作用而被猝灭。２０℃时荧光猝灭程度１ｎ（Ｆｏ／Ｆ）和Ｆ０／Ｆ分别与０～６．０×１０－６ｇ／ｍＬ和３．０×１０－６～８．０×１０－６ｇ／ｍＬ的 ｃｔＤＮＡ成线性关系。ｃｔＤＮＡ的这种猝灭行为与 Ｃｅ（Ⅲ）的荧光为 Ｈ２ＰＯ４的猝灭相似，猝灭等温线的斜率随温度增加略有增加。而高浓度 ｃｔＤＮＡ与Ｃｅ（Ⅲ）生成了在 ２９５．２ｎｍ处有吸收的复合物。
The fluorescence of cerium(Ⅲ ) emitted at 350. 0 nm when excited at 257. 0 nm in sodium chloride medium of pH<6. 2 was quenched by calf thymus DNA because of the elec- trostatic interaction of the positive species of cerium(Ⅲ ) in water with the negative charge of phosphate in calf thymus DNA. In the ranges 0～ 6. 0 ×10-６g/mL and 3. 0 ×10-6～8. 0 × 10-６ｇ/mL DNA, ln(F０/F) and F０/F had linear relationships with the concentration of DNA respectively. The quenching mechanism was proved similar to that of H２PO４ whose quench- ing effect was promoted with increasing temperature. UV spectrum showed that a complex of calf thymus DNA with cerium(Ⅲ ) formed which had absorption at 295. 2 nm.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1997年第7期768-772,共5页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金
国家教育委员会博士点基金资助项目
关键词
铈
氯化钠
荧光猝灭
DNA
CTDNA
Calf thymus deoxyribonucleic acid, cerium(Ⅲ), sodium chloride, fluorescence quenching
