Positive curvature in Stern-Volmer plot described by a generalized model for static quenching
Positive curvature in Stern-Volmer plot described by a generalized model for static quenching
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DOI：
10.1016/j.jlumin.2018.10.106
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发表时间：
2019-02-01
影响因子：
3.6
通讯作者：
Pizzoferrato, R.
中科院分区：
文献类型：
--
作者：
Ciotta, E.;Prosposito, P.;Pizzoferrato, R.
在广泛的荧光团/猝灭剂浓度范围内，研究了水溶液中Cu2+离子存在下的未折叠富勒烯纳米颗粒（unps）的荧光猝灭效应。尽管已知碳纳米颗粒与金属离子形成稳定的配合物，因此根据经典的Stern-Volmer方程，预计线性图的主要静态猝灭，但实验Stern-Volmer图显示出具有初始向上曲率的非线性行为。适用于任何荧光团/猝灭剂浓度值的广义静态猝灭模型与实验数据非常吻合，而无需引入任何二阶效应，例如在作用域模型或扩散限制过程中。此外，通过改变ubnp溶液的稀释度，我们可以研究猝灭比如何依赖于荧光团浓度，而标准模型预测它是恒定的。除了为静态猝灭的非线性模型提供了重要的测试外，我们相信本研究可以帮助在荧光传感等应用中找到灵敏度和信噪比优化的最佳参数。
The fluorescence quenching effect of unfolded-fullerene nanoparticles (UFNPs) in the presence of Cu2+ ions in water solution has been investigated for a broad range of fluorophore/quencher concentrations. The experimental Stern-Volmer plot exhibited a nonlinear behaviour with an initial upward curvature even though carbon nanoparticles are known to form stable complexes with metal ions and thus a dominant static quenching with a linear plot is expected according to the classical Stern-Volmer equation. A generalized model for static quenching, applicable to any value of fluorophore/quencher concentrations, provided a very good fit with the experimental data without the need to introduce any second-order effect, such as in the sphere of action model or diffusion-limited processes. Moreover, by changing the dilution of the UFNP solution, we could study how the quenching ratio depended on the fluorophore concentration, whereas it is predicted to be constant by the standard model. In addition to providing a significant test of the nonlinear model for static quenching, we believe this study could help find the best parameters for the optimization of sensitivity and signal-to-noise ratio in applications such as fluorescence sensing.