Researchers at the University of California, Santa Cruz, have received major funding from the National Institutes of Health to develop new sensor technology for biomedical applications. The project builds on earlier advances by UCSC researchers in optical and electrical sensing technologies and involves a broad interdisciplinary group of collaborators at UCSC and Brigham Young University.

Holger Schmidt, an associate professor of electrical engineering at UCSC, is principal investigator on the grant from the National Institute of Biomedical Imaging and Bioengineering, which will provide $1.6 million over four years for the sensor project.

"We aim to develop a new type of instrument that can do both electrical and optical sensing of single biomolecules, with all the components of the sensor ultimately integrated onto a chip," Schmidt said. "This would be the first device to provide both electrical and optical characterization of single molecules."

Potential applications for the new device include highly sensitive testing for medical diagnostics. It could also be a powerful tool for basic research in molecular biology.

In 2004, Schmidt and his coworkers reported the first demonstration of integrated optical waveguides with liquid cores. This technology, using the principle of antiresonant reflecting optical waveguides (ARROW), enables light propagation through tiny volumes of liquids on a chip. Since then, Schmidt has continued to work with Aaron Hawkins of Brigham Young University to optimize the properties of the liquid-core optical waveguides for use in sensor devices. The new project involves the collaboration of two other scientists at UCSC: David Deamer, professor of chemistry and biochemistry and acting chair of biomolecular engineering, and Harry Noller, Sinsheimer Professor of Molecular Biology.

Deamer has pioneered the development of nanopore devices for electrical sensing of single molecules. A nanopore is a tiny hole with dimensions on the order of nanometers (a nanometer is one billionth of a meter). Passage of a molecule through the hole generates a characteristic electrical signal. The team plans to integrate nanopores and liquid-core optical waveguides into the new sensor platform.

"The nanopore will act as a smart gate for entry of individual molecules into the channel of the waveguide," Schmidt said.

Noller is a leading authority on ribosomes, complex biomolecular machines that are the protein factories in all living cells. The researchers will use the new sensor platform to study individual ribosomes in action.

"In the integrated sensor, we will be able to study the ribosome without the need to immobilize it, so we hope to gain new understanding of how the ribosome works," Schmidt said.

The collaboration brings together researchers from three different departments at UCSC: the Departments of Electrical Engineering and Biomolecular Engineering, both in the Baskin School of Engineering, and the Department of Molecular, Cell, and Developmental Biology in the Division of Physical and Biological Sciences.

"This is a truly multidisciplinary collaboration," Schmidt said. "I am very excited about using integrated optics to investigate real problems in molecular biology."

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Note to reporters: You may contact Schmidt at (831) 459-1482 or hschmidt@soe.ucsc.edu.