A Single Carbon-Dot System Enabling Multiple Stimuli Activated Room-Temperature Phosphorescence

Abstract

Room-temperature phosphorescent carbon dots (RTPCDs) have attracted considerable interests due to their unique nanoluminescent characteristic with time resolution. However, it is still a formidable challenge to construct multiple stimuli-activated RTP behaviors on CDs. Since the address of this issue facilitates complex and high-regulatable phosphorescent applications, we here develop a novel strategy to achieve a multiple stimuli responsive phosphorescent activation on a single carbon-dot system (S-CDs), using persulfurated aromatic carboxylic acid as the precursor. The introduction of aromatic carbonyl groups and multiple S atoms can promote the intersystem crossing process to generate RTP characteristic of the produced CDs. Meanwhile, by introducing these functional surface groups into S-CDs, the RTP property can be activated by light, acid, and thermal stimuli in solution or in film state. In this way, multistimuli responsive and tunable RTP characteristics are realized in the single carbon-dot system. Based on this set of RTP properties, S-CDs is applied to photocontrolled imaging in living cells, anticounterfeit label, and multilevel information encryption. Our work will benefit the development of multifunctional nanomaterials together with extending their application scope.

Modulating multi-color room temperature phosphorescence emission for carbon dot composites with ultralong lifetime

“…Carbon dots, as zero-dimensional carbon-based nano-luminescent materials, have aroused enormous interest because of their low toxicity, facile synthesis, biocompatibility, high stability, and tunable optical properties. 14–22 In general, the optical properties of RTP CDs can be enhanced effectively by heteroatom doping that include F, 23 N, 24 P, 25 S, 26 etc. Besides, matrix-assisted synthesis is another important method to obtain RTP CDs by embedding CDs into a matrix such as cyanuric acid, 27 SiO 2 , 28 melamine, 29 polyvinyl alcohol (PVA) 30 and so on.…”

“…Recently, inspiring progress has been made using both methods. For example, Sun et al 26 developed a strategy to prepare a multiple stimuli-responsive (light, acid, and thermal stimuli) and tunable RTP CDs by introducing aromatic carbonyl groups and S atoms. Liang et al 31 developed a micro-wave method to achieve RTP CDs in 8 min with a phosphorescence lifetime of 487 ms. Ding et al 32 fabricated full-color CD composites with the emission range of 466–638 nm, the average lifetimes from 113.90 ms to 581.76 ms and the highest quantum yield of 29.98%.…”

Coumarin-Conjugated Macromolecular Probe for Sequential Stimuli-Mediated Activation

“…Bioorthogonal reactions are extensively utilized for protein modification, thereby endowing the specificity to monitor and capture proteins in vitro and in cells. − Multiple strategies, including click reactions, , protein coupling modifications, , or genetic codon expansion, , have emerged as valuable tools to increase the labeling accuracy of POIs. Among them, HaloTag technology offers a facile and rapid approach to install a bioorthogonal handle on POIs in a highly selective fashion. − HaloTag protein is an engineered haloalkane dehalogenase that covalently reacts with synthetic ligands comprising a chloroalkane linker with different functional modalities, such as fluorophores, ,− drugs, or resins . The covalent conjugation between HaloTag protein and the chloroalkane ligand is highly specific and irreversible in physiological conditions. − Therefore, it is desirable to utilize the HaloTag system to develop a protein-immobilized bioprobe for multiple applications.…”

Construction of Coumarin-Based Bioorthogonal Macromolecular Probes for Photoactivation

“…Fluorescence imaging techniques have been remarkably developed for the study of biological events over the past decades. − Modifications of biomolecules with photolabile fluorescent probes could provide a spatiotemporal fluorescence “off–on” mode upon photoactivation, − enabling the visualization of the localization and trafficking of biomolecules in living cells. − Coumarins are well known for bioimaging and biosensing because of their bright fluorescence and modifiable backbones. At the same time, coumarins also exist as potent chemical inhibitors in treating cancer. , We previously established a novel fluorescent inhibitor system , where photoactivatable coumarins integrated their fluorescence imaging characteristics with druggable backbones to achieve a stimulus-controllable drug release for cancer treatment. , However, it is still challenging for coumarin-based small-molecular probes to directly monitor single biomacromolecular species in cells because of the nonspecific localization resulting in unpredictable visualization.…”