In-Film Bioprocessing and Immunoanalysis with Electroaddressable Stimuli-Responsive Polysaccharides

Advances in thin-film fabrication are integral to enhancing the power of microelectronics while fabrication methods that allow the integration of biological molecules are enabling advances in bioelectronics. A thin-filmfabrication method that further extends the integration of biology with microelectronics by allowing living biological systems to be assembled, cultured, and analyzed on-chip with the aid of localized electrical signals is described. Specifically, the blending of two stimuli-responsive film-forming polysaccharides for electroaddressing is reported. The first, alginate, can electrodeposit by undergoing a localized sol–gel transition in response to electrode-imposed anodic signals. The second, agarose, can be co-deposited with alginate and forms a gel upon a temperature reduction. Electrodeposition of this dual polysaccharide network is observed to be a simple, rapid, and spatially selective means for assembly. The bioprocessing capabilities are examined by co-depositing a yeast clone engineered to display a variable lymphocyte receptor protein on the cell surface. Results demonstrate the in-film expansion and induction of this cell population. Analysis of the cells’ surface proteins is achieved by the electrophoretic delivery of immunoreagents into the film. These results demonstrate a simple and benign means to electroaddress hydrogel films for in-film bioprocessing and immunoanalysis.