The research effort of my group includes a wide range from organic and medicinal chemistry to materials and devices in the area of nano-bio-systems. Much of our expertise is concentrated at the supramolecular assembly of man-made artificial organic chemicals and nanostructures and their unique interactions with biological entities (such as proteins, DNA and biocompatible polymers). These endeavors span into the following areas:
We like to acknowledge Mr. Xiao-Ming Xu (a graduate student in the Dept.
of Pharmaceutics under the supervision of Prof. Diane J. Burgess) for the artistic rendering of this animation
SINGLE WALL CARBON NANOTUBES (SWNTs): The wrapping of SWNTs with a seamless, conformal helix made out of small molecular weight material has been a major challenge in the field of SWNTs. Our group has recently accomplished this with the help of flavin mononucleotide (Vitamin B2). Moreover, we have shown that this helical wrapping is capable to separate a single chirality sem-SWNT (i.e (8,6)) out of a mixture of more than 50 (Nature Nanotech., 2008, 3, 356). Separated SWNTs are poised to enhance considerably the properties of nanostructured devices. More recently, we have shown that the helical wrapping of a flavin derivative (FC12) is capable to increase SWNT photoluminescence efficiency as high as 20%. (Science, 2009, 323, 1319 (View Paper) The nature for this enrichment is based on the active desorption of 1,4-endoperoxide defects at nanotube lengths greater than 94 nm. The more luminescent the nanotube, the brighter they appears under infrared irradiation or by electrical excitation. This enables a number of important applications since different (n,m)-nanotube emissions are not only extremely sharp, but they also appear in a spectral region where minimal absorption or scattering takes place by soft tissue. Moreover, carbon nanotubes display superb photo bleaching stability and are ideally suited for near-infrared emitters, making them appropriate for applications in medicine and homeland security as bio-reporting agents and nano-sized beacons. SWNT luminescence also has also important applications in cancer therpy to antibody targeting and nano-scaled LEDs and photo detectors, which can readily integrate with silicon-based technology. Seamless self organization of FMN around SWNTs and its stability offers a great opportunity for loading antibody, drug, or special enzymes to target specific antigens in the cancer cells and their destruction.
CARBON NANOTUBE BIO-ELECTRONICS: Building on our initial finding of self-assembled SWNT forest arrays (JACS, 2001, 123, 9451), our group in conjunction with Prof. Rusling’s group has been able to electrically interface carbon nanotubes with redox enzymes (Electr. Comm., 2003, 5, 408-411) and produce highly sensitive electrochemical immunosensors (JACS, 2006, 128, 11199) with 100 ag sensitivity. With the recent addition of the NANOBIONICS DEVICE FABRICATION FACILITY within IMS, our group is currently interfacing these immunosensors within microfluidics devices.
We like to acknowledge Mr. Xiao-Ming Xu (a graduate student in the Dept.
of Pharmaceutics under the supervision of Prof. Diane J. Burgess) for the artistic rendering of this animation
TOTALLY IMPLANTABLE WIRELESS GLUCOSE SENSORS: Real time monitoring of various metabolic analytes that control function and physiology of the human body is crucially needed for a variety of applications and especially for diabetic patients in everyday life. Our group, in collaboration with the groups of Professors Burgess and Jain, has been developing wireless, totally implantable glucose sensors that exhibit significant size reduction, increased bio-acceptability and suppression of inflammation (J. Contr. Release, 2007, 117, 68). Significant effort is exerted to identify the various failure mechanisms and improve upon both sin-vitro and in-vivo device stability (J. Diabetes Sci. & Tech., 2007, 1(2), 193).
SEMICONDUCTOR NANOCRYSTALS (NCS): CdSe NCs are important luminescent markers for a variety of biological application. Our group has been developing selective growth and faceting methodologies for CdSe NCs (JACS, 2005, 127, 2524 & 2006, 128, 6280) as well as using them for tracking DNA transcription efficiencies for in vitro and in vivo applications (in collaboration with Prof. Burgess and Silbart) (Molecular Therapy, 2006, 14(2) 192)
