SBIR-STTR Award

Electrical wiring of redox enzymes, a novel basis for making biosensors, provides a powerful method of directly electrically sensing lactate. Biosensors based on the wired enzymes have advantages in accuracy, sensitivity speed, no leachable components, insensitivity to variation in oxygen partial pressure, insensitivity to interferants miniaturization (high signal level and small sample size), high stability, and small associated electronics. The specific aim of the Phase I research is to develop such a lactate sensor for use m plasma and serum. Experiments thus far have been conducted in buffer solution; related work on "wired" glucose enzyme electrodes has been successful in serum and plasma. The long term objective is to develop a sensor suitable for use in in vitro blood gas/electrolyte monitors commonly used in cardiac units and for possible incorporation into pulmonary artery catheters that are used to measure blood 02 and C02 levels and other parameters. Blood lactate concentrations are a sensitive marker for inadequate oxygen utilization and hence of cardiovascular or metabolic failure in critically-ill patients. If the patient is recovering from major cardiovascular or trauma surgery, a rise in blood lactate during recovery may guide the level and type of care required.Awardee's statement of the potential commercial applications of the research: The project will develop miniature lactate electrodes that will expand the functions of existing blood gas/electrolyte analyzers in critical care patient monitoring and in the diagnosis and management of circulatory disorders, e. g. sepsis. In Phase 11, electrodes will be developed for in vivo use in catheters during surgery.National Institute of General Medical Sciences (NIGMS)

Electrical "wiring" of redox enzymes, a novel basis for making biosensors, provides a powerful method of directly electrically sensing lactate. Biosensors based on the wired enzymes have advantages in accuracy, sensitivity, speed, no leachable components, low sensitivity to variation in oxygen partial pressure, insensitivity to interferants, miniaturization (high signal level and small sample size), and high stability. Lactate has been demonstrated to be the best indicator of inadequate tissue oxygenation, superior to oxygen measurement. Lactate monitoring has been demonstrated to be necessary in the prediction, diagnosis and treatment of hypoxia, sepsis, intra and postoperative surgical illnesses, organ failure, adult respiratory distress syndrome and cardiogenic shock.Phase II will develop prototype sensors for use in critical care m vitro blood gas1electrolyte analyzers, in vivo catheters (e.g., Swan-Ganz catheters) and microdialysis systems (for biomedical research). Blood gas monitors are commonly used to measure oxygen in the pulmonary artery during and after surgery. No commercial in vivo lactate sensors exlst today. Existing in vitro lactate analyzers are relatively oxygen sensitive, large, inaccurate, and/or require sample dilution.Awardee's statement of the potential commercial applieations of the research:Blood gas monitoring is an estimated $800 million market worldwide. Measurement of blood gases is the most frequently performed laboratory assay in intensive care units. A $50 million lactate monitoring market is projected by the year 2000 as lactate monitoring becomes clinically prevalent. Increased demand for lactate monitoring is driven by both medical and economical considerations. By reducing complications associated with the medical conditions noted above, health care costs are reduced.National Institute of General Medical Sciences (NIGMS)