Tunable Fluorescence of Graphdiyne Quantum Dots by Enlarging π System and Altering Electronic Structure

Extending the fluorescence of graphdiyne quantum-dot-derived materials beyond the predominantly reported blue-to-green region may broaden their use in fluorescence imaging and sensing. To address this issue, modified graphdiyne quantum dots (M-GDQDs) with green, yellow, and red fluorescence were first obtained by classical hydrothermal and solvothermal methods. Experimental and theoretical studies have shown that the enlargement of the π system and the changes in electronic structures contributed to the red shift in the fluorescence emission wavelength, although the individual contributions of conjugation and surface chemistry could not be quantitatively separated. The prepared M-GDQDs exhibit wonderful optical properties, good water solubility and excellent biocompatibility, which are beneficial for bioimaging. This study not only enriches the types of graphdiyne quantum dots, but it can also be used for the construction of multichannel fluorescent biosensing platforms. We believe that the emergence of M-GDQDs offers promising application prospects in the fields of nanomedicine and disease-related biomarker analysis.