Abstract In this Phase II SBIR, we will commercialize tissue-implantable 30 ?m microbiosensors to measure glucose, lactate and oxygen for use in freely moving animals. We will also develop and commercialize a sensor array composed of a glucose biosensor, a lactate biosensor and an oxygen sensor. Biosensors provide high temporal resolution and low analyte consumption when compared to microdialysis. Current, state-of-the-art biosensors (O.D. 100-250 ?m), have proven value in the measurement of a range of analytes in the brains of freely moving rodents. Reduction of biosensor diameter will result in considerably less damage to brain tissue and improved anatomical accuracy over current microdialysis and biosensor techniques. Pinnacle will lead this proposal and work in conjunction with an interdisciplinary consortium of three leading scientists at the University of Kansas. Professor Shenqiang Ren possesses extensive experience in materials science and nanofabrication techniques, Professor Mark Richter is skilled in protein engineering, and Professor George Wilson brings over 30 years of experience in biosensor development to the project. The facilities and equipment available at Pinnacle and the various University of Kansas laboratories will provide the resources required to successfully complete this project. Innovative aspects of this proposal include: new technologies in biosensor manufacturing such as nanoetching, and electrophoretically manipulated enzyme-immobilized nanoparticles and the ability to routinely and precisely deposit picoliters of substrate into a defined well. In Phase I,our team made several significant advancements in the development of a prototype 30 ?m glucose microbiosensor. We produced functional prototypes that measured glucose in a linear fashion to at least 20 mM, rejected ascorbate and urate, and efficiently recycled O2 at the electrode surface. These preliminary results form the foundation for the Phase II proposal. These implantable 30 ?m microbiosensors have the potential to significantly increase the understanding of the mechanisms behind drug-neuron interactions. This will profoundly change the drug discovery landscape and improve drug development efficiencies for pharmaceutical and biotech companies. In addition, increased spatial resolution and decreased inflammation responses will allow researchers to identify new neural processes, leading to new understandings, approaches and solutions for common maladies. Biosensor sales in FY2009 were $6.9 billion with 31% of the sales due to human glucose sensors. Pinnacle is an established manufacturer of biosensors and is well positioned to introduce this new class of biosensors to a broad market.