健那绿B的荧光猝灭研究及作为核酸测定探针的应用

用紫外可见光谱、稳态荧光发射及荧光寿命测定研究了核酸猝灭十二烷基磺酸钠胶束中的健那绿荧光。水溶液中弱的健那绿荧光在十二烷基磺酸钠胶束中被大大加强，其最大发射从425纳米移至410纳米，核酸的加入将猝灭健那绿的荧光，当健那绿浓度为2.5×10^–5 mol•L^-1时，荧光猝灭(F₀/F)分别与小牛胸腺DNA及鱼精DNA在2.4×10^–8 到 1.08×10^–7及 1.9×10^–8 到 3.8×10^–8 mol•L^-1范围内成正比, 检测限分别为1.3×10^–8 mol•L^-1 (小牛胸腺DNA)及6.3×10^–9 mol•L^-1 (鱼精DNA)。当DNA浓度较高时, 将系统偏离Stern-Volmer方程。这是因为动态猝灭和静态猝灭同时存在。方法已应用于鸡血提取液中DNA的测定, 测定结果与紫外法一致。

Fluorescence Quenching Investigation for Janus Green B and used as Probe in Determination of Nucleic Acids

Fluorescence quenching of janus green B (JGB) in sodium dodecyl sulfate (SDS) micelle by nucleic acids (DNA) was studied using UV‐vis absorption, steady state fluorescence emission methods and lifetime measurements. In the SDS micelle, weak fluorescence of JGB was enhanced, and the maximum emission shifted from 425 to 410 nm. In the presence of DNA, the fluorescence of JGB was quenched. Linear relationships between the fluorescence quenching (F₀/F) and concentrations of DNA were observed in the range of 2.4×10^?8 to 1.08×10^?7 mol·L^?1 for calf thymus nucleic acids (ct DNA) and 1.9×10^?8 to 3.8×10^?8 mol·L^?1 for fish sperm nucleic acids (fs DNA) when 2.5×10^?5 mol·L^?1 JGB was employed. The limit detection were 1.3×10^?8 mol·L^?1 for ct DNA and 6.4×10^?9 mol·L^?1 for fs DNA. At high DNA concentration, there was a systematic deviation from the Stern‐Volmer equation due to the static and dynamic quenching occurring simultaneously. The proposed method was applied to the determination of the nucleic acids in chicken blood extraction and the analytical results were in good agreement with the UV‐method.