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molecular level [15]. 

<img src='content_image/346098.jpg'>

Once the DNCs were characterized, the water was removed with a micro-pipette and the substrate was left to dry overnight under a gentle stream of nitrogen. In the last phase of the experiment, TiO 2 particles were placed on the sample (see Fig. 1d). Figures 2c and d show the fluorescence and iSCAT images in the scattering medium. The individual DNCs are still easily identified via fluorescence, while the scattering image now displays a “speckle” pattern. Figures 4a-f present the measured lifetimes of many DNCs from three different scattering samples (the step with water was omitted for samples 2 and 3). Let us label the fluorescence lifetime in the scattering medium by τ s . As in the case of water immersion, we found a distribution of the normalized fluorescence lifetimes τ s /τ a , indicating both reduction and enhancement of the spontaneous emission rate. However, while in the previous case the average value 〈 τ w /τ a 〉 < 1, here we find 〈 τ s /τ a 〉 > 1. In sample 1, for example, fluorescence lifetimes are longer than in air by up to a factor of 1.4 with an ensemble average of 1.1. The histograms of Figs. 4b, d, f reveal variations in the measurements from the three samples. 

