Simple Strategy for Scalable Preparation Carbon Dots: RTP, Time‐Dependent Fluorescence, and NIR Behaviors

Abstract

Transforming carbon dots (CDs) fluorescent materials into smart materials with complex functions is a topic of great interest to nanoscience. However, designing CDs with regulating fluorescence/phosphorescence that can be visually monitored with the environment changes in real-time remains a challenge. Here, a very simple strategy, one-step solvent-free catalytic assistant strategy, which is low cost, facile, environment-friendly, and high throughput, is put forward. Hydrogen bond is used to manipulate nanostructure of CDs, and the obtained carbon dots (M-CDs) show a series of attractive properties including matrix-free room-temperature phosphorescence, time-dependent fluorescence, and near-infrared emissive characteristics. Different from the traditional aggregation caused quenching or aggregation-induced emission fluorescent materials, M-CDs exhibit unprecedented and unique dispersion induced redshift fluorescence phenomenon, promoting the studies of fluorescence from static to dynamic. The causes of this phenomenon are further analyzed in detail. As a kind of intelligent fluorescent materials, this new designed CDs greatly enrich the basic recognition of CDs by illustrating the relationship between redshift fluorescence behaviors and the dispersion states, and may provide with an opportunity for solid-state fluorescent materials, anti-counterfeiting, cellular imaging, and hopefully many others.

Electrochemical control of emission enhancement in solid-state nitrogen-doped carbon quantum dots

“…1b proves the existence of element N. The peaks at 1710 cm −1 , 1660 cm −1 and 1410 cm −1 can be attributed to the stretching vibrations of CO, CN and C–N bonds, respectively. 28 The vibrational absorption bands at 3420 cm −1 and 3250 cm −1 indicate the presence of amino (–NH 2 ) and hydroxyl (–OH) groups on N-CQDs. 29,30 The existence of a large number of hydrophilic groups on the surface, such as –NH 2 and –OH, makes N-CQDs have good water solubility.…”

Evolution and fabrication of carbon dot-based room temperature phosphorescence materials

“…Currently, researchers often choose polymers or their monomers, cross-linkable reactants, molecules doped with heteroatoms and larger conjugated structures as precursors. 86–96,98–109,131,132 The relevant achievements are shown in Table 2.…”

Red emissive carbon dots as a fluorescent sensor for fast specific monitoring and imaging of polarity in living cells

“…By contrast, a fluorescent sensor made from nanoparticles has excellent biological affinity and unique photoelectric characteristics, 26–29 especially for those which are built up by choosing carbon as the basic framework of nanometer quantum dots, not only endowing them with diversified structural variability and abundant modifiability, but also enjoying the advantages of abundant and affordable precursors, green and convenient synthesis procedures as well as exceptional characteristics, such as excellent water solubility, negligible toxicity, and terrific biocompatibility. 30–33 These advantages make carbon quantum dots particularly suitable for the real-time detection and imaging of biological activity markers in multitudinous biological events, including polarity response. 34–37…”