Shang Li, Dong Shaojun
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Changchun, 130022, China.
Anal Chem. 2009 Feb 15;81(4):1465-70. doi: 10.1021/ac802281x.
We have demonstrated the design of a new type fluorescent assay based on the inner filter effect (IFE) of metal nanoparticles (NPs), which is conceptually different from the previously reported metal NPs-based fluorescent assays. With a high extinction coefficient and tunable plasmon absorption feature, metal NPs are expected to be capable of functioning as a powerful absorber to tune the emission of the fluorophore in the IFE-based fluorescent assays. In this work, we presented two proof-of-concept examples based on the IFE of Au NPs by choosing MDMO-PPV as a model fluorophore, whose fluorescence could be tuned by the absorbance of Au NPs with a much higher sensitivity than the corresponding absorbance approach. While the first assay worked in a turn-on mode upon the etching of Au NPs by the analyte, CN(-), the second one functioned in a turn-off mode upon the catalytic growth of Au NPs by the analyte, H(2)O(2). As a result, the present IFE-based approach can detect cyanide ranging from 1.0 x 10(-6) to 6.0 x 10(-4) M with a detection limit of 6.0 x 10(-7) M and H(2)O(2) ranging from 1.5 x 10(-7) to 2.2 x 10(-5) M with a detection limit of 8.5 x 10(-8) M, respectively. Notably, the present IFE-based approach allows the design of fluorescent assays in a more simple, time-saving, and economical approach when compared with conventional metal NPs-based fluorescent assays, since no modification step of the fluorophore was needed any more.
我们展示了一种基于金属纳米颗粒（NPs）内滤效应（IFE）的新型荧光分析方法的设计，这在概念上与先前报道的基于金属NPs的荧光分析方法不同。由于具有高消光系数和可调谐的等离子体吸收特性，金属NPs有望在基于IFE的荧光分析中作为强大的吸收体来调节荧光团的发射。在这项工作中，我们通过选择MDMO-PPV作为模型荧光团，给出了两个基于金纳米颗粒IFE的概念验证示例，其荧光可通过金纳米颗粒的吸光度进行调节，灵敏度远高于相应的吸光方法。第一种分析方法在分析物CN(-)蚀刻金纳米颗粒时以开启模式工作，而第二种方法在分析物H(2)O(2)催化金纳米颗粒生长时以关闭模式工作。结果，目前基于IFE的方法能够分别检测浓度范围为1.0×10(-6)至6.0×10(-4)M的氰化物，检测限为6.0×10(-7)M，以及浓度范围为1.5×10(-7)至2.2×10(-5)M的H(2)O(2)，检测限为8.5×10(-8)M。值得注意的是，与传统的基于金属NPs的荧光分析方法相比，目前基于IFE的方法能够以更简单、省时且经济的方式设计荧光分析，因为不再需要对荧光团进行修饰步骤。
