Research On Electrodeposition Technology Of Chitosan/quantum Dots And Chitosan/coordinating Metal Ions

Microelectronics and biotechnology are two kinds of fastest-growing technology in the 20 th century. In the 21 th century, scientists hope to integrate biology with electronics for further applications. Recently, many researchers have studied the electrodeposition of some stimuli-responsive biomacromolecules, in which the electrodeposition of chitosan has received the most widely intention. Electrodeposition of chitosan has many advantages, such as simple and rapid process, mild condition, and precise spatiotemporal control, which can be widely used in biosensors, drug controlled release, energy storage materials, and biological fuel cell. In this work, we investigate the electrodeposition of chitosan and quantum dots, as well as the electrodeposition of chitosan and coordinating metal ions.Quantum dots(QDs) have been widely used in many fields(such as biological detection, bioimaging, biosensors and fluorescent patterns) due to their special physical and chemical properties. In this work, we study the technology of electrodeposition of chitosan and ZnS QDs. We prepared aqueous ZnS QDs using an aqueous one-step method, constructed ZnS QDs and chitosan composite by electrodeposition on different conductive substrates, and then fabricated the fluorescent patterns by employing the electrodes with various shapes and the protective coating. We also studied the effects of electrodeposition conditions on fluorescence property of the co-deposited surface. The results show that chitosan/ZnS QDs can be electrodeposited onto different kinds of substrates(e.g., gold, silver, titanium and 316 L stainless steel) and the chitosan/QDs deposited films exhibit clearly blue fluorescence. In addition, the fluorescence intensity of co-deposited surfaces enhances with the increase of deposition time and concentration of ZnS QDs. Specifically, diverse fluorescent patterns can be constructed by electroaddressing chitosan/QDs composite at the localized region, or by employing electrodes with various shapes. It has also been found that the fluorescent patterns of chitosan/QDs composite have reproducibility. We anticipate that this method may have broad applications for photoluminescence devices, fluorescent coatings, and nanocomposite biodevices.Furthermore, chitosan hydrogel can be generated by coordination between metal ions and chitosan. In this study, we prepared chitosan/Cu2+ hydrogels by electrodeposition using copper as anode and platinum plate as cathode. We carried out a serial of experiments and tests to verify this electrodeposition mechanism, then studied the effects of electrodeposition conditions(e.g., pH of the chitosan solution, time, and voltage) on the electrodepositon of chitosan/Cu2+ hydrogels, and also studied the applications of this new kind of electrodeposition technology. The results show that there are stable chitosan hydrogels on the surface of copper plates, and the chitosan/Cu2+ hydrogel has smooth surface and no bubbles in it. Specifically, the hydrogel shows clear blue color, which is accordant with the color of Cu2+. The thickness of chitosan/metal ion hydrogel can be controlled by adjusting electrodeposition conditions, and this electrodeposition process to construct chitosan/Cu2+ hydrogel has spatiotemporal control and selectivity, also has selectivity for metal ions for features. This electrodeposition for generating chitosan/Cu2+ hydrogel provide a novel, simply and controllable method for chitosan deposition. We also expect this method of constructing chitosan/Cu2+ hydrogel may provide a strategy for applications in bio-devices, protein immobilization, patterned coatings, and controlled drug release.