Dispersion-assisted tunable fluorescence from carbon dots

In this study, carbon dots (CDs) synthesized by hydrothermal method with amino-rich surface exhibit tunable fluorescence across entire visible range by simply controlling the concentration. A comprehensive comparison has been performed for the first time between concentration-induced aggregation of the single-type CDs and electrostatic-induced agglomeration of opposite-charged CDs in terms of their fluorescence properties. Experimental results show that both the aggregation of CDs and internal absorption filtration are possible causes of the concentration-dependent fluorescence emission. Subsequently, the inter distance of adjacent CDs in their aggregates was enlarged by forming rigid double-stranded DNA (dsDNA) between adjacent CDs through base pairing. It is clear that the contact of CDs induces the changes of fluorescence emission and light absorption. Through a better understanding of the mechanisms behind concentration-induced multicolor emission, this work can provide a novel strategy to develop the advanced applications of CDs.

Automated summary

In this study, tunable fluorescence across the entire visible range was achieved in carbon dots (CDs) synthesized by hydrothermal method with amino-rich surface by simply controlling the concentration. The effects of concentration-induced aggregation and electrostatic-induced agglomeration were compared for the first time in terms of their fluorescence properties. It was found that both the aggregation of CDs and internal absorption filtration can cause concentration-dependent fluorescence emission. Additionally, the inter distance of adjacent CDs in their aggregates was enlarged by forming rigid double-stranded DNA (dsDNA) between adjacent CDs through base pairing.