Full-Color Emission Polymer Carbon Dots with Quench-Resistant Solid-State Fluorescence.

Jieren Shao,Shoujun Zhu,Bai Yang,Yubin Song,Songyuan Tao,Huiwen Liu

doi:10.1002/advs.201700395

Jieren Shao, Shoujun Zhu + Show 4 more

Open Access

https://doi.org/10.1002/advs.201700395

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Abstract

Polymer carbon dots (PCDs) represent a new class of carbon dots (CDs) possessing sub‐fluorophores and unique polymer‐like structures. However, like small molecule dyes and traditional CDs, PCDs often suffer from self‐quenching effect in solid state, limiting their potential applications. Moreover, it is hard to prepare PCDs that have the same chemical structure, exhibiting full‐color emission under one fixed excitation wavelength by only modulating the concentration of the PCDs. Herein, self‐quenching‐resistant solid‐state fluorescent polymer carbon dots (SSFPCDs) are prepared, which exhibit strong red SSF without any other additional solid matrices, while having a large production yield (≈89%) and a considerable quantum yield of 8.50%. When dispersed in water or solid matrices in gradient concentrations, they can exhibit yellow, green, and blue fluorescence, realizing the first SSFPCDs with the same chemical structure emitting in full‐color range by changing the ratio of SSFPCDs to the solid matrices.

Highlights

Is affected by heteroatom doping and finite size effects,[20,21] the Polymer carbon dots (PCDs) only possess possessing sub-fluorophores and unique polymer-like structures
When dispersed in water or solid matrices in gradient concentrations, they can exhibit yellow, green, and blue fluorescence, realizing the first SSFPCDs through physical immobilization or chemical crosslinking of polymer chains, which is entitled to the crosslink enhanced emission (CEE) effect.[5,7,22,23]
During CEE process, the rotation and vibration with the same chemical structure emitting in full-color range by changing the of these sub-fluorophores are efficiently ratio of SSFPCDs to the solid matrices

Summary

Introduction

Is affected by heteroatom doping and finite size effects,[20,21] the PCDs only possess possessing sub-fluorophores and unique polymer-like structures. Under UV excitation (365 nm), the dilute solution of SSFPCDs (1 mg mL−1) displayed strong blue fluorescence (460 nm) with the fluorescence QY of 18.9%, and exhibited excitation dependence, indicating several excited states existing in SSFPCDs.[38,47] Because the as-prepared SSFPCDs have undergone a strict purification process, there is no extra small molecules contaminating the dots, as a result, the fluorescence is really originated from the SSFPCDs. Besides the basic analysis and characterization above, some novel findings were exhibited to investigate the emission center of PCDs. First, excited by UV light (365 nm), the SSFPCDs powder showed strong red SSF (625 nm) unlike other reported PCDs, which do not have luminescence in the solid state because of the aggregation-caused luminescence quenching (Figure 1d).

Results

Conclusion