Controllable and high-pressure gas driven microfluidic platform towards large-scale fabrication of multicolor-emissive carbon dots

Abstract

In recent years, the rapid advancement of carbon dots (CDs) has established them as highly promising candidates in the field of fluorescent nanomaterials. Microfluidic technology, known for its efficiency in nanomaterial synthesis, has encountered significant challenges in the production of CDs due to insufficient fluid driving force, a consequence of the high-pressure conditions generated in microfluidic channels during high-temperature reactions. This limitation has significantly constrained the application of microfluidic technology in synthesis of CDs. To address this issue, this study developed a controllable, high-pressure gas driven microfluidic platform, enabling the large-scale production of CDs with multicolor fluorescence emission. By precisely regulating the pressure in feedstock tank and the opening of control valves, continuous and stable fluid flow and reactions were maintained in high-temperature heated channels, even when using low-boiling-point solvents. Adjustments in reaction temperature and precursor selection facilitated the large-scale synthesis of CDs emitting blue, green, yellow, and red fluorescence (B-CDs, G-CDs, Y-CDs and R-CDs). Furthermore, the excellent biocompatibility and low toxicity of the G-CDs enabled the successful application in cellular imaging. This work provides a novel solution to the challenge of insufficient fluid driving force in microfluidic synthesis of CDs, and it is expected to promote further advancements in the use of microfluidic technology for large-scale production functional nanomaterial.