Electrodeposition of a carbon dots/chitosan composite produced by a simple in situ method and electrically controlled release of carbon dots
Carbon dots (CDs), a new type of fluorescent nanomaterial, have drawn considerable attention due to their attractive applications in biolabeling, bioimaging and fluorescent probes. Here, a CDs/chitosan composite that can be straightforwardly used for further electrodeposition and electrically controlled release of CDs, was produced by a simple and novel in situ method based on a one-step microwave treatment of a chitosan solution. We choose the chitosan solution as the only reactant for producing the CDs/chitosan composite, because chitosan can not only serve as the precursor for preparing the CDs, but can also be frequently used for the electrodeposition. Importantly, the prepared CDs/chitosan composite is not only endowed with multicolor fluorescence features coming from the CDs, but also retains the pH-responsive film-forming properties of chitosan. On the basis of these favorable properties, we can straightforwardly employ the CDs/chitosan composite to construct fluorescent coatings, as well as a variety of multicolor fluorescent patterns on different electrodes or substrates through the electrodeposition technique. More interestingly, the release of CDs in the electrodeposited coatings or patterns can be controlled by electrical signals. Consequently, this CDs/chitosan composite with straightforward applications in electrodeposition and electrically controlled release of CDs is promising for use in photoluminescent coatings, fluorescent patterns, fluorescent labeling, and controlled release.