| There have been enormous scientific interests in research on cell adhesion processes mediated by specific interactions between cell surface receptors and ligands presented on extracellular matrix. Dynamic substrates that modulate cell-substrate interactions by changing compositions of ligands in real time would provide unprecedented opportunities for a variety of applications, including the study of heterotypic cell-cell interactions and the regulation of cells by the extracellular matrix. In the first part of the thesis, are discussed several classes of electroactive interfaces which can manipulate the activities of immobilized ligands in real-time, and therefore modulate adherent cells.; In the second part, a new assay method for enzyme activity and a label-free detection method for protein-protein interactions are presented. Self-assembled monolayers on gold were combined with MALDI-ToF MS for the detection of biological or biochemical events such as enzymatic modification of substrate molecules and protein-protein interactions without any labels. The use of label-free detection method can identify the full range of biochemical activities on biochips and allow the discovery of unanticipated activities. |
