Luminescence modulation of carbon dots assemblies

摘要

Integrating multi-emissive color in one platform provides a possible way to avoid background interference or to obtain white light. Thus, different luminescent units, including quantum dots, dyes, and rare-earth ions, are generally mixed, composited or embedded in a single matrix. However, this is a very cumbersome process. In the present work, double-and triple-emissive carbon dots (Cdots) assemblies were constructed using cost-effective, easy-accessible blue-emission Cdots as a precursor. The Cdots assemblies built by the crosslinking reactions between the amine groups of triethylenetetramine (TETA)passivating Cdots and the aldehyde groups of glutaraldehyde (GA), showed photoluminescence (PL) peaks at 460, 559 and 656 nm. Furthermore, the assemblies formed from Cdots passivated with 1,8-diamine-3,6-dioxaoctane (DADO) exhibited double PL. Structural characterization and selective probe reactions showed that the multi-color emissions of Cdots assemblies should be from new fluorophore centers consisting of abundant imine bonds in a condensed microenvironment. When using the ink of TETA-Cdots assemblies to write alphabet letters, upon irradiation with different light, they showed abundant and variable colors, showing their potential application in anti-counterfeiting devices and white light-emitting diodes. This work provides a novel design, as well as a simple and practical technology, to obtain multi-color luminescent materials, and to tune the emission of Cdots.