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 linkligand-induced folding in biopolymers (e.g.peptides,nucleicacids) to a robust,electrochemical signaling mechanism.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 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, indiumtinoxide ), in particular, materials that are compatible with the fabrication of low-cost, high-quality sensor arrays.
Undergraduate, graduate students and postdoctoral researchers in my group can expect to receive training in fundamental electrochemistry, analyticalchemistry, general biosensor design and fabrication. They also gain significant exposure to one or more of the following specialties: Design of electrochemical and /or optical-based biosensors; biomaterials-electrode interface characterization; protein engineering, applications of electrogenerated chemiluminescence.
An electrochemical peptide-based (E-PB) 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.
Folding-based Electrochemical DNA Sensor Fabricated by “Click” Chemistry. Ca?ete, S. J. P.; Yang, W.; Lai, R. Y. ChemComm., 2009, in press, DOI:10.1039/b911273a.
Folding-based Electrochemical DNA Sensor Fabricated on a Gold-plated Screen-printed Carbon Electrode. Yang, W.; Gerasimov J. Y.; Lai, R. Y. ChemComm., 2009,20, 2902-2904.
Continuous, Real-Time Monitoring of Cocaine in Undiluted Blood Serum via a Microfluidic, Electrochemical Aptamer-Based Sensor. Swensen, J. S.; Xiao, Y.; Ferguson, B. S.; Lubin, A. A.; Lai, R. Y.; Heeger, A. J.; Plaxco, K. W.; Soh, H. T. J. Am. Chem. Soc., 2009, 131, 4262 -4266.
Preparation of Electrode-immobilized, Redox-modified Oligonucleotides for Electrochemical DNA and Aptamer-based Sensing. Xiao, Y.; Lai, R. Y.; Plaxco, K. W. Nature Protocols, 2007, 2, 2875-2880.
Aptamer-Based Electrochemical Detection of PicomolarPlatelet-Derived Growth Factor Directly in Blood Serum. Lai, R. Y.; Plaxco, K. W.; Heeger, A. J., Anal. Chem., 2007, 79, 229-233.
Rapid, Sequence-Specific Detection of Unpurified PCR AmpliconsVia a Reusable, Electronic Sensor. Lai, R. Y.; Legally, E. T.; Lee, S-H.; Soh, H. T.; Plaxco, K. W.; Heeger, A. J., Proc. Natl. Acad. Sci., 2006, 103, 4017-4021.