Supramolecular self-assembly of carbon nanodots through edge functionalized interaction

Control of aggregation plays an important role in the photophysical behavior of luminescent nanomaterials . Herein, the concentration-dependent self-assembled hybrid of carbon nanodots (CDs) with the alteration spectral characters of H-/J-aggregation were observed. In detail, the CDs aging under different conditions presented obvious spectral variations ranging from visible to near-infrared regions, accompanied by the spontaneous evolution of nanoaggregates from CD nanoparticles . Theoretical calculations and experimental results confirmed the inhomogeneous surface functional groups could render CDs into nanoaggregates with the H- or J-aggregation through intraparticle or interparticle interaction, inducing the discrepant surface-confined charges in these intraparticle nanoaggregates and further contributing to their shift of absorption and emission bands. With the novel aggregation regulation, the CDs exhibited a tunable increase in their photothermal and photodynamic capability in comparison to their original counterparts. These findings shed a new light on the understanding of the photophysical behaviors for the self-assembled hybrid of CDs with the concept of supramolecular engineering.