Protiveris Inc, a bio-nanotechnology company commercializing proprietary bioMEMS technologies to facilitate protein research and the discovery of new pharmaceuticals, announced the completion of a 1x64 Vertical Cavity Surface Emitting Laser (VCSEL) module - a critical component in the development of their microcantilever array reader.

When implemented as part of the Protiveris optical reader, the 1x64 VCSEL array enables assays to be performed in a high-throughput fashion. The number of cantilevers that can be illuminated at once directly translates into the number of tests that can be performed simultaneously. Protiveris' MOSAIC (Micro-Optical SubAssembly for Illuminating Microcantilevers) device contains a linear array of 64 individually addressable VCSELs on a 250-micron pitch. A fused silica microlens array placed over the VCSELs focuses the laser beams onto the microcantilevers.

"The MOSAIC and its use of Vertical Cavity Surface Emitting Lasers is critical to the development of our biosensor system," said Tim Seeley, Vice President of Engineering. "Our product development and engineering has progressed significantly with the inclusion of this device and its technology."

Protiveris' microfluidic protein biochip system and optical reader utilizes arrays of microcantilevers with customizable surfaces to measure distinct biomolecular interactions, including interactions between proteins, antibodies, antigens, or DNA. This robust platform can be used for a variety of biopharmaceutical applications including ligand fishing, comparative protein expression profiling, panel testing, toxicity profiling, and protein expression screening. The chip's sensitivity allows for use of nanoliters of sample volumes, significantly less volume than current technologies, thereby preserving precious reagents such as chemical libraries.

The optical output stability of VCSEL arrays is dependent on several variables including device structure, current drive, and temperature. In the Protiveris reader, the MOSAIC device is housed in a robust package and is designed to plug into a zero-insertion force (ZIF) socket. A thermoelectric cooler mounted in the ZIF socket maintains the MOSAIC at a stable operating temperature while a flex circuit provides the electrical interconnect between a high density connector and the VCSEL array. Power output and heat removal are therefore managed through constant current VCSEL drivers and a simple interface to a thermoelectric cooler. Should the MOSAIC require service or replacement, the MOSAIC design permits easy removal from its socket.

The Protiveris technology is based on chemo-mechanical actuation of specially designed silicon microcantilevers and subsequent optical detection of the microcantilever deflections. Through microfluidics, a combination of attachment chemistries selectively and covalently links a probe biomolecule to the gold surface of a microcantilever. When coated on one side with antibodies, antigens, proteins, peptides, or DNA/RNA, the microcantilever will bend when it is exposed to a solution containing complementary molecules. This bending is caused by the change in the surface energy due to the binding event. To analyze these results, Protiveris has developed patented optical readers and software to detect, measure, and interpret these binding reactions.