Induction of long-lived room temperature phosphorescence of carbon dots by water in hydrogen-bonded matrices

Abstract

Phosphorescence shows great potential for application in bioimaging and ion detection because of its long-lived luminescence and high signal-to-noise ratio, but establishing phosphorescence emission in aqueous environments remains a challenge. Herein, we present a general design strategy that effectively promotes phosphorescence by utilising water molecules to construct hydrogen-bonded networks between carbon dots (CDs) and cyanuric acid (CA). Interestingly, water molecules not only cause no phosphorescence quenching but also greatly enhance the phosphorescence emission. This enhancement behaviour can be explained by the fact that the highly ordered bound water on the CA particle surface can construct robust bridge-like hydrogen-bonded networks between the CDs and CA, which not only effectively rigidifies the C=O bonds of the CDs but also greatly enhances the rigidity of the entire system. In addition, the CD-CA suspension exhibits a high phosphorescence lifetime (687 ms) and is successfully applied in ion detection based on its visible phosphorescence.

Excitons in Carbonic Nanostructures

“…Accordingly, the phosphorescence of C-dots was detected when they were incorporated into solids, such as polymer films [324]. In H-aggregated molecular assemblies of organic dyes, a bright room-temperature phosphorescence was achieved in solid powders [325] and even in water solutions [326] due to the fact of their special design [327]. Meanwhile, the basic mechanism of their triplet exciton generation [321,328] remains unclear as well as in nanocarbon systems.…”

Hydrochromic carbon dots as smart sensors for water sensing in organic solvents

“…Taking into account the low hydrochromism of CD5, it is straightforward to conclude that the water-promoted hydrogen bonded network is itself not sufficient to induce the uorescence changes in carbon dots. [69][70][71] Fig . 4 Visual colorimetric water sensing performance of hydrated aprotic THF.…”

The Effect of Poly (Ethylene Glycol) on the Photoluminescence Properties of Carbon Dots From Cassava Peels Synthesized by Hydrothermal Methods

“…The electron time decay of C-dots can be obtained from the fitting decay curve which satisfies the multi-exponential decay function as in EQ. (1) as follows [25][26][27]:…”