(14i) Nanostructured Based Lab-on-Chips for Detection of Single Biomolecules

Nanostructured materials and nanofabricated lab-on-chip devices can play pivotal roles in biomedical research applications including genetic diagnosis and sensitive pathogen detection. Identifying genetic disorders or disease states on-chip requires dynamic manipulation and efficient trapping of a small number of molecules of the target nucleic acid. Current technologies are limited either by sensor resolution or by trapping a low concentration of molecules at the detection sites. Inspired by the state of the art nanofabrication and nano-synthesis methods, my research is focused on designing and fabricating lab-on-chip devices and nanostructured electrodes to overcome these limitations.

In order to enhance the detection sites for biomolecules in low concentration analytes (e.g. Dopamine) I have developed metallic/metal oxide nanostructures with an extended surface area for electro-chemical and biochemical reactions. I have adopted a similar approach to develop nanostructured surfaces to efficiently immobilize DNA and proteins, as part of assays to indirectly detect a wide range of biomolecules. I use electrochemical and lithography techniques to fabricate nanotubular and nanowire structured electrodes as well as nano/microfabricated diagnostics platforms. The platforms have successfully been used for sensitive detection of biomolecules such as dopamine, glucose, uric acid and ascorbic acid as well as pathogens such as Escherichia coli and Staphylococcus aureus.

To further improve trapping efficiency of the target sample on the detection sites, I have developed a sample-delivery system based on reversible, tunable nanofluidic confinement of biomolecules based on the dielectrophoretic force, applied using Silicon Nitride and Indium Tin Oxide nano-patterned electrodes. The resulting device can concentrate and manipulate molecules at high throughput; and can be used to create open-access and simple designs that can be easily interfaced with microfluidic devices for buffer exchange and sample processing; and integrated with optical detectors or on-chip nanostructured electrodes to detect single biomolecules (such DNA fragments up to 100,000 base pairs in length). The ease of fabrication and uncomplicated instrumentation makes this technology a unique point of care instrument for optical detection of biomolecules.

To immediately initiate my research program as a faculty member, I envision three potential projects: (1) Graphene-TiO₂ electrodes for biological and chemical detection, (2) ITO/SiN_x device with programmable electrodes for Cell/DNA sorting and analysis, and (3) 3D Microelectrodes based lab-on-chip for study biochemical reactions.

Teaching Interests:

I would be interested in applying my teaching principles to a wide range of undergraduate and graduate courses in Thermodynamics, Kinetics Fluid Mechanics, Heat Transfer, Transport phenomena, Mass Balances, Biomedical image analysis, Materials properties and characterization, Mechanics of materials, Biomechanics, Fluid Mechanics, Biomedical Instrumentation, tissue engineering, Engineering design, Bio/nanoelectronics. I would like to pursue the development of more specialized courses in biomedical engineering such as Bio/nanomaterials, biosensors, design of medical devices and nanofabrication methods. The fields of materials science along with the current explosions in biomedical engineering and nanotechnology offer many opportunities for the development of interdisciplinary courses.