We report a new electrodeposition method for chitosan based on the coordination of chitosan to metal ions in situ-generated by simultaneous electrochemical oxidation.

No abstract

A carbon dots/chitosan composite that can be straightforwardly used for electrodeposition and controlled release was produced by a one-step microwave method.

Electroaddressing is an attractive method for triggering assembly of stimuli-responsive biopolymers with exquisite spatiotemporal control, and it also offers a controllable means to concurrently assemble biological materials and nanoparticles for a diverse range of applications. Here, we demonstrate a novel method to construct fluorescent and patterned device surfaces by electroaddressing of quantum dots (QDs)/chitosan composite. First, the surfaces of ZnS QDs/chitosan composite on the electrodes are built by electrodeposition method. It is shown that the deposited surface displays clear fluorescence under UV light, and the fluorescence intensity of the surface can be controlled by electrodeposition conditions (e.g., deposition time). Furthermore, a variety of fluorescent patterns can be constructed by employing electrodes or substrates with various shapes. Specifically, taking advantage of the spatiotemporal selectivity of electroaddressing and the pH-responsive property of chitosan, we construct diverse fluorescent patterns by electroaddressing QDs/chitosan composite at the localized region. It is also found that the fluorescent patterns of QDs/chitosan composite have reproducibility. Thus, this work presents a convenient, versatile, and controllable method to construct fluorescent and patterned device surface by electroaddressing, which has promising applications in photoluminescence device, fluorescent and patterned coating, and nanocomposite biodevice.

2015): A simple approach to generate fluorescent quantum dots/gelatin composite with thermo-responsive and reversible sol-gel transition, Soft Materials, AbstractStimuli-responsive sol-gel transitions of biopolymers triggered by stimuli (e.g., temperature, pH, light and electric field) have received tremendous attention due to their potential applications in controlled release of drugs, tissue engineering, and new functional materials. Here, we use a simple approach to generate a fluorescent composite of quantum dots/gelatin with reversible sol-gel transition triggered by temperature stimuli. We initially prepared the aqueous CdS quantum dots with clear yellow fluorescence by a single-step process. These CdS quantum dots Downloaded by [UQ Library] at 03:54 23 June 2015A c c e p t e d M a n u s c r i p t 2 can reserve their fluorescence after they were combined with gelatin. Specifically, rheological measurements and vial inversion tests both confirm that CdS quantum dots/gelatin composite can undergo reversible sol-gel transition initiated by temperature stimuli near physiological temperature. Furthermore, it is shown that loading, preservation and release of CdS quantum dots in aqueous medium can be controlled by adjusting the temperature to trigger the sol-gel transition of the composite. Consequently, it can be expected that this fluorescent quantum dots/gelatin composite with thermo-responsive and reversible sol-gel transition has promising applications in biomedical fields such as bioimaging, biosensing and drug delivery.