Self-quenching-resistant carbon dots with tunable solid-state fluorescence

Abstract

Aggregation-caused quenching (ACQ) of carbon dots (CDs) is the main obstacle to their solid-state application. Herein, self-quenching-resistant CDs with tunable solid-state fluorescence (SSF) were obtained via the electrochemical method in separate electrodes simultaneously, where redox reactions from the cathode and anode are employed to develop a differentiated strategy for surface-state modulation through molecular modification. The key feature of this approach is the tunable emission from morphological changes of o-phenylenediamine within the anode and cathode, and considerable steric hindrance from long chains and guanidino groups on CDs introduced by D-arginine. The guanidino groups, in particular, enhanced spatial steric hindrance in situ and suppressed ACQ through a hydrogen-bonding network. Furthermore, such SSF CDs with emission at 550 nm (Y-CDs) and a main emission at 646 nm (R-CDs) exhibit great potential for applications in light emitting diodes (LEDs) and multi-mode anti-counterfeiting.