Nano Sensors Group | Illinois

Nano Sensors Group in the News

2007

  • September 25, 2007 - Researchers set new record for brightness of quantum dots

    James E. Kloeppel, Physical Sciences Editor
    217-244-1073; kloeppel@uiuc.edu

    Brian Cunningham, professor of electrical and computer engineering, left, and graduate students, from left, Nikhil Ganesh, Wei Zhang and Patrick Mathias have set a new record for brightness of quantum dots.

    CHAMPAIGN, Ill. — By placing quantum dots on a specially designed photonic crystal, researchers at the University of Illinois have demonstrated enhanced fluorescence intensity by a factor of up to 108. Potential applications include high-brightness light-emitting diodes, optical switches and personalized, high-sensitivity biosensors.

    “We are using photonic crystals in a new way,” said Brian Cunningham, a professor of electrical and computer engineering and corresponding author of a paper published in the August issue of the journal Nature Nanotechnology, and featured on the cover (image on the right side of the web page). “We tune them to the specific wavelength of a laser used to stimulate the quantum dots, which couples the energy more efficiently and increases the brightness.”

    A quantum dot is a tiny piece of semiconductor material 2 to 10 nanometers in diameter (a nanometer is 1 billionth of a meter). When illuminated with invisible ultraviolet light, a quantum dot will fluoresce with visible light. To enhance the fluorescence, Cunningham and colleagues at the U. of I. begin by creating plastic sheets of photonic crystal using a technique called replica molding. Then they fasten commercially available quantum dots to the surface of the plastic.“We designed the photonic crystal to efficiently capture the light from an ultraviolet laser and to concentrate its intensity right within the surface where the quantum dots are located,” said Cunningham, who also is affiliated with the university’s Beckman Institute, the Micro and Nanotechnology Laboratory, and the Institute for Genomic Biology. “Enhanced absorption by the quantum dots is the first improvement we made.”

    Enhanced, directed emission from the quantum dots is the second improvement. Quantum dots normally give off light in all directions. However, because the researchers’ quantum dots are sitting on a photonic crystal, the energy can be channeled in a preferred direction – toward a detector, for example. While the researchers report an enhancement of fluorescence intensity by a factor of up to 108 compared with quantum dots on an unpatterned surface, more recent (unpublished) work has exceeded a factor of 550. “The enhanced brightness makes it feasible to use photonic crystals and quantum dots in biosensing applications from detecting DNA and other biomolecules, to detecting cancer cells, spores and viruses,” Cunningham said. “More exotic applications, such as personalized medicine based on an individual’s genetic profile, may also be possible.”

Funding was provided by the National Science Foundation and SRU Biosystems. Part of the work was carried out in the university’s Center for Microanalysis of Materials, which is partially supported by the U.S. Department of Energy.

  • March 28, 2007 SRU Biosystems Secures Exclusive License to Evanescent Resonance Technology for Optimized Drug Discovery and Diagnostics

    -Highly Sensitive Luminescence-based Label Technology Complements Company's Existing Label-free Detection Capabilities-

    Woburn, Massachusetts, March 28, 2007 – SRU Biosystems, a leader in highly sensitive labeled and label-free detection technologies, today announced that it has secured an exclusive license to Evanescent Resonance (ER) technology, a detection platform that enhances the sensitivity of fluorescence-based assays for drug discovery and diagnostics. Novartis has granted SRU the exclusive rights to the ER technology for use in drug discovery, as well as all supporting intellectual property rights. The sensitivity of ER technology should make it possible to profile the entire genome utilizing minute samples, or to perform ultra-sensitive ELISAs.

    “The addition of ER technology to our portfolio means that SRU has the most sensitive labeled and label-free detection technology at our fingertips,” commented Owen Dempsey, President and CEO of SRU Biosystems. “We are excited to bring the capabilities of both the ER platform and our label-free BIND® system together in ways never used before that may enhance companies’ drug discovery and diagnostics efforts. This technology works with virtually any luminescence-based label, while increasing assay sensitivity 100-fold. Additionally, this technology, which is incorporated into standard microarray slides and microtiter plates, is compatible with existing infrastructure and commercial equipment on the market, furthering its commercial attractiveness to researchers.”

    The ER technology is a luminescence-based platform that utilizes an optical amplification to enhance signal intensities, which in one embodiment enables precise measurement of gene expression from very small samples that include less than one nanogram of RNA; traditional microarrays require much more RNA for gene expression profiling. Utilizing ER, the fluorophores attached to samples are excited more efficiently when compared to standard assays, resulting in up to a 100-fold increase in the level of fluorescence signals and corresponding improved detection limits.

  • January 17, 2007 - Illinois and Pakistani researchers team for cancer cures

    Researchers at Illinois are teaming up with counterparts in Pakistan to develop nanotechnologies which will identify potential cancer therapies which utilize native medicinal plants. “The Indo-Pakistan subcontinent is rich in such remedial sources, most of which remain untouched,” explained Kenneth Watkin, co-director and lead principle investigator (PI) for the “Nanomedicine for Cancer” research project, which is being funded by the Pakistan-U.S. Science and Technology Cooperative Program.

    “My research focuses on the development and application of new methods of biomedical imaging for diagnosis and treatment,” stated Watkin, a professor in the College of Applied Health Sciences. “Pakistan is among the eight leading exporters of medicinal plants. There is a need to build partnerships that help provide the infra-structure and training for the application and utilization of recently developed new rapid screening techniques for evidenced based evaluation of various plant extracts.” Watkins stated that proteins, the key elements of the biological machinery, are involved in a variety of functions such as modulation of the immune system, regulation and processing of hormones, protein degradation and processing, signal transduction, programmed cell death etc. in addition to the normal metabolic processes.

    “We have employed a new label-free optical biosensor system for high throughput evaluation,” said Watkin, who is also the director of the Medical Imaging Research Laboratory, which is a part of the Bioimaging Science and Technology Group at Beckman Institute for Advanced Science and Technology.

    “This new biosensor system is being used for rapid evaluation of the breast cancer apoptotic potential of plant extracts. Our preliminary research revealed several potential extracts that kill breast cancer cells. The potential cancer treatment extract candidates will progress to clinical evaluation,” stated co-PI Brian Cunningham, an associate professor of electrical and computer engineering at Illinois.

    “The application of this type of nanomedicine technology has enormous potential not only for the treatment of cancer but also for the medicinal plant industry in Pakistan. Applications include high throughput pharmaceutical compound screening, molecular diagnostics, PCR, electrophoresis, label-free microarrays, proteomics, environmental detection, and whole-cell assays,” said Irfan Ahmad, associate director for the Center for Nanoscale Science and Technology (CNST), who is a co-director/co-PI on the project.

    “This research award also highlights the College of Engineering's (COE) growing partnerships with other colleges on campus such as the Applied Health Sciences through the Center for Nanoscale Science and Technology,” stated COE dean Ilesanmi Adesida.

    “The research also will be conducted at the newly established bionanotechnology section of the Micro and Nanotechnology Laboratory,” said Ahmad. The University of Illinois’ research team includes Watkin, Ahmad, Cunningham, and Hanafy Fouly, a research specialist/plant pathologist in the Department of Natural Resources and Environmental Science at the College of Agricultural, Consumer, and Environmental Sciences. The co-director/PI on the Pakistani side of the project is Atiya Abbasi of the International Center for Chemical Sciences, H.E.J. Research Institute of Chemistry and Dr. Panjwani Center for Molecular Medicine & Drug Research at the University of Karachi.

    The joint research proposalsubmitted under the Pakistan-US Science and Technology Cooperative Program for 2006 was one of only 13 selected from among the 121 applications. The selection committee has recommended U.S. funding for the project at a total level of $250,000 over three years.

    As stated in the proposal, Pakistan has the third highest cancer rate of all thirteen South-Central Asian countries. The most prevalent cancers for men are, in rank order, lung, bladder, esophagus, non-Hodgkins lymphoma and colon cancer. The most prevalent cancers for women, in rank order, are breast, oral, ovarian and cervical cancer. More than 70% of the developing world's population still depends on the complementary and alternative systems of medicine (CAM).Evidence-based CAM therapies have shown remarkable success in healing acute as well as chronic diseases. There is a definite need to design training and capacity-building programs for the CAM practitioners who need such continuing education, hence bringing them into the mainstream and elevating their status in society.