APPLICATIONS OF TECHNOLOGY:
- Drug design, screening, and in vivo testing
- Clinical laboratory assays
- Biomedical research
- Inexpensive implementation
- Can be achieved with a standard bench top spectrophotometer
- Scales up for high throughput
- Records real-time binding kinetics
- High signal-to-noise ratio
- Label-free detection
Jay Groves and colleagues at Berkeley Lab have developed a label free technique for optically detecting, in real time, the binding of molecules to a membrane surface. The method produces a straightforward readout on a spectrophotometer by measuring changes in localized surface plasmon resonance (LSPR) on cubic nanoparticles coupled to a membrane that is essentially identical to that of a cell. The nanocubes are fabricated easily, and the assay can be executed with inexpensive equipment. This technology could be applied to any research that involves ligand-receptor binding on membranes, possibly including cell-to-cell binding.
The silver nanocubes are adsorbed directly onto a glass slide and coated with a lipid membrane that can be constructed, if desired, to contain receptors or other biomolecules, such as oligonucleotides. The device is then exposed to a solution of analytes, i.e., molecules that may or may not bind to the membrane components. If specific binding occurs, it quantifiably changes the LSPR spectra of the underlying nanocubes, and a standard spectrophotometer detects this change at a high signal-to-noise ratio (approximately 42). The spectrophotometer provides real time data that reflects dynamic binding and unbinding, allowing for kinetic analyses and the measurement of binding affinity.
The entire fabrication and preparation of the assay is achieved through chemical self-assembly without the need for complex and expensive patterning or lithography. The method can also be scaled up for simultaneous applications in a multiwell plate to allow for high throughput. Until now, nanostructure-based sensors have required complicated nanoparticle fabrication and instrumentation that cannot quickly process multiple samples. Similarly, most plasmonic detection systems have been incompatible with membranes. The Berkeley Lab invention overcomes these limitations.
DEVELOPMENT STAGE: Proof of principle.
STATUS: Published patent application US2010/023375 available at www.wipo.int. Available for licensing or collaborative research.
FOR MORE INFORMATION:
Galush W.J., S.A. Shelby, M.J. Mulvihill, A. Tao, P. Yang, J.T. Groves. “A nanocube plasmonic sensor for molecular binding on membrane surfaces,” Nano Letters. 9(5):2077-2082 (2009).
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
REFERENCE NUMBER: JIB-2649