University of Nebraska-Lincoln
651 Hamilton Hall
Lincoln, NE 68588-0304
Teaching and Research Interests
Our research program focuses on both fundamental and applied aspects of biosensor research. The main objective of our research is the design and fabrication of folding- and dynamics-based electrochemical biosensors. We aim at developing portable real-time biosensors for environmental monitoring and point-of-care diagnostics. Our sensing strategy is to link target-induced change in the conformation and/or flexibility of the biorecognition elements (e.g. peptides, nucleic acids) to a robust, electrochemical signaling mechanism. These sensors are reagentless, reusable, and insensitive to non-specific interactions of contaminants, enabling them to be employed directly in realistically complex media such as blood, urine, soil extracts, and a wide range of food matrices.
Our research also encompasses the use of other analytical techniques such as electrochemical-surface plasmon resonance spectroscopy, spectroscopic ellipsometry, quartz crystal microbalance with dissipation, scanning electrochemical microscopy, and fluorescence microscopy for characterization of biosensors.
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.
Selected Publications1) Use of Thiolated Oligonucleotides as Anti-fouling Diluents in Electrochemical Peptide-based Sensors. McQuistan, A.; Zaitouna, A. J.; Echeverria, E.; Lai, R. Y., Chem. Commun., 2014, DOI:10.1039/C4CC01290A.
2) Fabrication of Electrochemical DNA Sensors on Gold-modified Recessed Platinum Nanoelectrodes. Salamifar, S. E.; Lai, R. Y., Anal. Chem., 2014, 86, 2849-2852.
3) Three-Dimensional Periodic Graphene Nanostructures. Wilson, P.; Mbah, G.N.; Smith, T.G.; Schmidt, D.; Lai, R. Y.; Hofmann, T.; Sinitskii, A. J. Mater. Chem. C, 2014, 2, 1879-1886.
4) Characterization of an Electrochemical Mercury Sensor Using Alternating Current, Cyclic, Square Wave and Differential Pulse Voltammetry. Guerreiro, G. V.; Zaitouna, A. J.; Lai, R. Y. Analytica Chimica Acta, 2014, 810, 79-85.
5) Use of Combined Scanning Electrochemical and Fluorescence Microscopy for Detection of Reactive Oxygen Species in Prostate Cancer Cells. Salamifar, S. E.; Lai, R. Y. Anal. Chem., 2013, 85, 9417-9421.
6) Electrochemical Techniques for Characterization of Stem-loop Probe and Linear Probe-based DNA Sensors. Lai, R. Y.; Walker, B.; Stormberg, K.; Zaitouna, A. J.; Yang, W. Methods, 2013, 64, 267-275.
7) “Signal-on” Electrochemical DNA Sensor with an Oligo-thymine Spacer for Point Mutation Detection. Wu, Y.; Lai, R. Y. Chem. Commun. 2013, 49, 3422-3424.
8) The Effect of Signaling Probe Conformation on Sensor Performance of a Displacement-based Electrochemical DNA Sensor. Yu, Z.; Lai, R. Y. Anal. Chem., 2013, 85, 3340-3346.
9) Development of an Electrochemical Insulin Sensor Based on the Insulin-linked Polymorphic Region. Gerasimov, J. Y.; Schaefer, C. S.; Yang, W.; Grout, R. L.; Lai, R. Y. Biosensors and Bioelectronics, 2013, 42, 62-68.
10) Design and Characterization of an Electrochemical Peptide-based Sensor Fabricated via “Click” Chemistry. Gerasimov, J. Y.; Lai, R. Y. Chem. Commun. 2011, 47, 8688-8690.
11) A Folding-based Electrochemical Aptasensor for Detection of Vascular Endothelial Growth Factor in Human Whole Blood. Zhao, S.; Yang, W.; Lai, R. Y. Biosensors and Bioelectronics, 2011, 26, 2442-2447.
12) Fabrication of an Electrochemical DNA Sensor Array via Potential-assisted “Click” Chemistry. Caňete, S. J. P.; Lai, R. Y. Chem. Commun., 2010, 46, 3941-3943.