Our research program is comprised of both fundamental and applicational aspects of biosensor research. The main objective of our research involves the design of folding-based electrochemical biosensors, with the goal of developing a portable real-time biosensor for point-of-care diagnosis. Our sensing strategy is to link ligand-induced folding in biopolymers (e.g. peptides, nucleic acids) to a robust, electrochemical signaling mechanism (Figure 1). Unlike most optical-based biosensors, these sensors are reagentless, reusable, and insensitive to non-specific interactions of contaminants, thus allowing them to be employed directly in realistically complex media such as blood serum and urine.
Our research also encompasses the engineering of new or improved protein scaffolds (e.g. periplasmic binding protein, calmodulin) for biosensor applications. Part of our research effort is to further understand protein-electrode interactions, with the aim at improving sensor performance and stability. We are also interested in exploring various electrode materials (e.g. carbon, indium tin oxide), in particular, materials that are compatible with the fabrication of low-cost, high-quality sensor arrays.
An electrochemical protein sensor fabricated by self-assembly of a peptide probe labeled with a redox molecule (methylene-blue (MB)) on a gold electrode surface. In the absence of target antibody, the peptide probe is thought to be highly dynamic, enabling efficient electron transfer between the MB label and the electrode. Upon target binding, the MB label is physically sequestered from the electrode surface, therefore impeding electron transfer which leads to a significant reduction in the MB peak current.
Figure 1. Peptide-based Electrochemical Biosensor