Tunable Photoluminescence Across the Entire Visible Spectrum from Carbon Dots Excited by White Light
Tunable Photoluminescence Across the Entire Visible Spectrum from Carbon Dots Excited by White Light
复制标题
白光激发的碳点在整个可见光谱范围内可调谐光致发光
DOI：
10.1002/anie.201411004
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发表时间：
2015-03-02
影响因子：
16.6
通讯作者：
Cole, Ivan
中科院分区：
文献类型：
--
作者：
Hu, Shengliang;Trinchi, Adrian;Cole, Ivan
尽管有报道表明，由于激发波长的变化，碳点发射波长发生了变化，但这种依赖于激发的发射并不构成真正的调谐，因为移位的峰的强度比其主要发射的强度弱得多，这在现实世界的应用中往往是不受欢迎的。我们首次报道了碳点的合成和光致发光性质，这些碳点的峰值荧光发射波长可以通过简单的调整试剂和合成条件在整个可见光谱范围内进行调节，这些碳点是由白光激发的。详细的材料表征表明，这种可调发射是由于碳化过程中发生的脱氢反应导致碳点化学成分的变化造成的。这些都显著改变了成核和生长过程，导致点具有更多的含氧或含氮基团，最终决定了它们的光致发光性质，这与以前观察到的碳点激发依赖的荧光形成了鲜明的对比。这种合成具有可调峰值发射的宽带可激发碳点的新能力开辟了许多新的可能性，特别是在多模式传感中，通过将特定的碳点发射波长与特定的化学过程相关联，可以同时监测多个分析物和过程，而不需要调节激发源。
Although reports have shown shifts in carbon dot emission wavelengths resulting from varying the excitation wavelength, this excitation-dependent emission does not constitute true tuning, as the shifted peaks have much weaker intensity than their dominant emission, and this is often undesired in real world applications. We report for the first time the synthesis and photoluminescence properties of carbon dots whose peak fluorescence emission wavelengths are tunable across the entire visible spectrum by simple adjustment of the reagents and synthesis conditions, and these carbon dots are excited by white light. Detailed material characterization has revealed that this tunable emission results from changes in the carbon dots' chemical composition, dictated by dehydrogenation reactions occurring during carbonization. These significantly alter the nucleation and growth process, resulting in dots with either more oxygen-containing or nitrogen-containing groups that ultimately determine their photoluminescence properties, which is in stark contrast to previous observations of carbon dot excitation-dependent fluorescence. This new ability to synthesize broadband excitable carbon dots with tunable peak emissions opens up many new possibilities, particularly in multimodal sensing, in which multiple analytes and processes could be monitored simultaneously by associating a particular carbon dot emission wavelength to a specific chemical process without the need for tuning the excitation source.