Research Interests

The research in our lab focuses on developing novel detection techniques for biological molecules, with an emphasis on “real-time” detecting methodologies. Our work involves design and synthesis of functional materials capable of effective optical or electrical signaling, and use of surface plasmon resonance (SPR) spectroscopy and imaging techniques for characterization and measurements.

I. Biosensors

Biosensors are molecule-based devices that transduce a biochemical process or a binding event into a measurable signal. A typical biosensor consists of a receptor that defines specificity and a transducer that generates signals. Our biosensor research is directed at establishing effective signal transduction pathways through functionalization of supramolecular assemblies with cell surface constituents. Current research efforts are centered at membrane-based biosensors fabricated with supported lipid bilayer membranes. We are interested in design of robust membrane arrays, use of membranes for suppressing non-specific interactions in immunoassay, and detection of membrane-targeting bacterial toxins and other biomolecules. In addition, we employ microfabrication techniques to build sensor chips capable of self-calibration and signal amplification to enhance detection sensitivity and lower false positive response rates.

II. Functional Biomaterials

The ability to precisely control molecular arrangements developed in nanotechnology holds forth the promise of a completely new generation of advanced materials. We are interested in using these principles for design and fabrication of novel materials for analytical applications. The current systems consist of functional conjugated polymers of polydiacetylenes (PDA) and polythiophenes (PT). In addition to colorimetric detection employing the unique optical properties of the polymers, we also seek to develop new concepts that expand the applications into new territories. One good example for such an expansion is the development of "turn-on" fluorescent sensors with PDA assemblies.

III. Bio-interfaces

To design effective biosensors, the nature of molecular interactions between the target and receptor molecules must be fully understood. We are interested in studying the affinity properties by developing new surface plasmon resonance spectroscopy and imaging techniques. SPR is a quantum optical-electrical phenomenon capable of sensitive and quantitative measurement of a broad spectrum of chemical and biological entities without the need of a label. Since the phenomenon of SPR is completely nonspecific, rational design of the sensing interface is critical. The analytical aspects of SPR bio-interface study include ultrasensitive detection of toxins, multiplexed array analysis, and signal amplification through various mechanisms. Coupling SPR with other analytical techniques for simultaneous quantification and identification is also being explored.

Selected Publications:

Zhuangzhi Wang, Thomas Wilkop, Danke Xu, Yi Dong, Guangyu Ma, and Quan Cheng. Surface Plasmon Resonance Imaging for Affinity Analysis of Aptamer-Protein Interactions with PDMS Microfluidic Chips, Anal. Bioanal. Chem. 2007, 389, 819-825.

Thomas W. Owen, Rabih O. Al-Kaysi, Christopher J. Bardeen and Quan Cheng. Microgravimetric Immunosensor for Direct Detection of Aerosolized Influenza A Virus Particles, Sens. Actuators B, 2007, 126, 691-699.

Joseph D. Taylor, K. Scott Phillips, Quan Cheng. Microfluidic Fabrication of Addressable Tethered Lipid Bilayer Arrays and Optimization Using SPR with Silane-Derivatized Nanoglassy Substrates, Lab Chip, 2007, 7, 927-930.

K. Scott Phillips and Quan Cheng. Recent Advances in Surface Plasmon Resonance Based Techniques for Bioanalysis, Anal. Bioanal. Chem. 2007, 387, 1831-1840.

K. Scott Phillips, Jong Ho Han, and Quan Cheng. Development of a 'Membrane Cloaking' Method for Amperometric Enzyme Immunoassay and Surface Plasmon Resonance Analysis of Proteins in Serum Samples, Anal. Chem. 2007, 79, 899-907.

Thomas Wilkop, Danke Xu and Quan Cheng. Characterization of Pore Formation by Streptolysin O on Supported Lipid Membranes by Impedance Spectroscopy and Surface Plasmon Resonance Spectroscopy, Langmuir, 2007, 23, 1403-1409.

Na Zhang, Thomas Wilkop, Soohyun Lee and Quan Cheng. Bi-Functionalization of a Patterned Prussian Blue Array for Dual-Potential Amperometric Detection of Glucose, Analyst, 2007, 132, 164-172.

Xiaobo Yu, Danke Xu and Quan Cheng. Label-Free Detection Methods for Protein Microarrays, Proteomics, 2006, 6, 5493-5503.

Guangyu Ma and Quan Cheng. Manipulating FRET with Polymeric Vesicles: Development of a "Mix-and-Detect" Type Fluorescence Sensor for Bacterial Toxin, Langmuir, 2006, 22, 6743-6745.

K. Scott Phillips, Thomas Wilkop, Jiing-Jong Wu, Rabih O. Al-Kaysi, and Quan Cheng. SPR Imaging Analysis of Protein-Receptor Binding in Supported Membrane Arrays on Gold Substrates with Calcinated Silicate Films, J. Amer. Chem. Soc. 2006, 128, 9590-9591.

Yi Dong, K. Scott Phillips and Quan Cheng. Immunosensing of Staphylococcus Enterotoxin B (SEB) in Milk with PDMS Microfluidic Systems Using Reinforced Supported Bilayer Membranes (r-SBMs), Lab-on-a-Chip, 2006, 6, 675 - 681.

K. Scott Phillips, Jung-Ho Han, Marilyn Martinez, Zhuangzhi Wang, David Carter and Quan Cheng. Nanoscale glassification of gold substrates for surface plasmon resonance analysis of protein toxins with supported lipid membranes, Anal. Chem. 2006, 78, 596-603

Guangyu Ma, Astrid M. Müller, Christopher J. Bardeen and Quan Cheng. Self-Assembly Combined with Photopolymerization for the Fabrication of Fluorescence "Turn-On" Vesicle Sensors with Reversible "On-Off" Switching Properties, Adv. Mater. 2006, 18, 55-60.

Zhuangzhi Wang, Thomas Wilkop, and Quan Cheng. Characterization of Micropatterned Lipid Membranes on a Gold Surface by Surface Plasmon Resonance Imaging and Electrochemical Signaling of a Pore-Forming Protein, Langmuir, 2005, 21, 10292-10296.

Guangyu Ma and Quan Cheng, A Vesicular Polydiacetylene Sensor for Colorimetric Signaling of Bacterial Pore-Forming Toxin, Langmuir, 2005, 21, 6123-6126.

Guangyu Ma and Quan Cheng. A nanoscale vesicular polydiacetylene sensor for organic amines by fluorescence recovery, Talanta, 2005, 67, 514 - 519.

K. Scott Phillips and Quan Cheng. Microfluidic Immunoassay for Bacterial Toxins with Supported Phospholipid Bilayer Membranes on PDMS, Anal. Chem. 2005, 77, 327-334.

Yoshihisa Amano and Quan Cheng. Detection of Influenza Virus: Traditional Approaches and Development of Biosensors, Anal. Bioanal. Chem. 2005, 381, 156–164.

K. Scott Phillips, Yi Dong, David Carter, and Quan Cheng. Stable and Fluid Ethylphosphocholine Membranes in a Poly(dimethylsiloxane) Microsensor for Toxin Detection in Flooded Waters, Anal. Chem. 2005, 77, 2960-2965.

Thomas Wilkop, Zhuangzhi Wang and Quan Cheng. Analysis of m-contact printed protein patterns by SPR imaging with a LED light source, Langmuir 2004, 20, 11141-11148.