Sombers Lab

Monitoring with Enzyme Modified Electrodes

The function and survival of brain tissue depends on sufficient supplies of glucose and oxygen via the blood stream. Thus, the detection of brain glucose dynamics in real time is imperative for understanding brain energy utilization in healthy tissue, as well as in understanding adaptations that occur in neuropathologies or upon exposure to substances of abuse. The Sombers lab has developed a microbiosensor (Lugo-Morales et. al., Analytical Chemistry 2013) and combined it with fast scan cyclic voltammetry to simultaneously monitor the chemical dynamics associated with metabolic events and dopaminergic cell function in real time (dopamine, glucose, oxygen). The microbiosensor employs an enzyme to produce H2O2 in the presence of the co-substrates, glucose and oxygen. This H2O2 is detected voltammetrically, using a novel approach that provides unprecedented temporal and spatial resolution, as well as the ability to monitor multiple chemical species at one recording site. We are using this tool to investigate the relationship between dopaminergic function and the local supply of glucose and oxygen to the region.

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Lugo-Morales L.Z., Loziuk P.L.*, Corder A.K.*, Toups J.V., Roberts J.G., McCaffrey K.A., Sombers L.A.Enzyme-Modified Carbon-Fiber Microelectrode for the Quantification of Dynamic Fluctuations of Nonelectroactive Analytes Using Fast-Scan Cyclic Voltammetry. Anal. Chem. 2013, 85: 8780-8786.  

Figure 2 from Smith S.K., Lee C.A., Dausch M.E., Horman B.M., Patisaul H.B., McCarty G.S., Sombers L.A. Simultaneous Voltammetric Measurements of Glucose and Dopamine Demonstrate the Coupling of Glucose Availability with Increased Metabolic Demand in the Rat Striatum. ACS Chemical Neurosci., In press. DOI: 10.1021/acschemneuro.6b00363