We report the facile synthesis of carbon dots with tunable fluorescence from unzipping of photonic crystals and their application in LEDs, which may provide an insight into the creation of multifunctional carbon dots adapted for various applications such as in optoelectronics, sensing, or bioimaging.

We report a simple, low-cost and green route for fabrication of fluorescent carbon dots (CDs), and demonstrate their applications in sensing, patterning, and coding. Pyrolysis of various plant leaves yielded bright blue-emitting CDs, providing a one-step way for large-scale production of CDs without surface passivation treatment or the use of toxic/expensive solvents and starting materials. Also, further improvement in the fluorescence intensity of CDs was achieved after treatment using plasma and microwave-assisted techniques. The obtained CDs were applied as a fluorescent sensing platform for sensitive and selective detection of Fe³⁺ ions, and as fluorescent inks for printing luminescent patterns useful in anti-counterfeit and optoelectronic applications. Moreover, uniform fluorescent microbeads of polymer-encapsulated CDs, CD/QD nanocomposites, and CD/organic fluorescent dye nanocomposites were prepared via a microfluidic process, which may expand the potential applications of CDs in coding, bioimaging, and drug delivery.

The pH value in the wound milieu plays a key role in cellular processes and cell cycle processes involved in the process of wound healing. Here, a microfluidic assembly technique is employed to fabricate micro‐gel ensembles that can precisely tune the pH value of wound surface and accelerate wound healing. The micro‐gel ensembles consist of poly (hydroxypropyl acrylate‐co‐acrylic acid)‐magnesium ions (poly‐(HPA‐co‐AA)‐Mg²⁺) gel and carboxymethyl chitosan (CMCS) gel, which can release and absorb hydrogen ion (H⁺) separately at different stages of healing in response to the evolution of wound microenvironment. By regulating the wound pH to affect the proliferation and migration of cell on the wound and the activity of various biological factors in the wound, the physiological processes are greatly facilitated which results in much accelerated healing of chronic wound. This work presents an effective strategy in designing wound healing materials with vast potentials for chronic wound management.