Electrochemically Induced Deposition of a Polysaccharide Hydrogel onto a Patterned Surface
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- 作者：Rohan Fernandes ; Li-Qun Wu ; Tianhong Chen ; Hyunmin Yi ; Gary W. Rubloff ; Reza Ghodssi ; William E. Bentley ; and Gregory F. Payne
- 刊名：Langmuir
- 出版年：2003
- 出版时间：May 13, 2003
- 年：2003
- 卷：19
- 期：10
- 页码：4058 - 4062
- 全文大小：376K
- 年卷期：v.19,no.10(May 13, 2003)
- ISSN：1520-5827
文摘
Hydrogels are increasingly considered for creating three-dimensional structures in miniaturized devices,yet few techniques exist for creating such hydrogel structures. We report a new approach for creatinghydrogels using the amine-containing polysaccharide chitosan. Specifically, electrodes are immersed intoa slightly acidic chitosan solution and a voltage is applied to promote the proton-consuming hydrogenevolution reaction at the cathode surface. This reaction leads to a high localized pH in the vicinity of thecathode surface, and if this localized pH exceeds about 6.3, then chitosan becomes insoluble and depositsat the cathode surface. As the current density is increased, the region of high pH is expected to extendfurther from the cathode surface into the bulk solution. Using moderately high current densities (50 A/m2),we observed that chitosan deposited as a thick hydrogel. Measurements of the water content confirmedthat the deposited chitosan was a hydrogel. To suggest the potential utility, we deposited a chitosanhydrogel on a patterned surface to create a channel. Because of chitosan's pH-dependent solubility, thischannel could be "disassembled" by mild acid treatment. We envision that electrochemically-induceddeposition of chitosan-based hydrogels may offer interesting opportunities for the integration of biologicalsystems into miniaturized devices.