Session: Analytical Division Poster:

Hypersensitive detection of blood and cerebrospinal fluid solutes is essential in medical testing and diagnosis. This is extended in surgical situations where immediate observations of solute concentrations can be largely beneficial to the practitioner, or for research in a laboratory setting. Current methods of analysis rely on drawing blood for a glucometer to determine concentration using glucose oxidase in conjunction with other enzymes. We aim to develop an ultrasensitive glucose detection technique which allows for real time detection of glucose concentrations in a variety of biological samples (cerebrospinal fluid, blood, urine, etc.). Poly(3,4-ethylenedioxythiophene) in combination with functionalized carbon nanotubes adhered to the exterior of electrode surface has proven to increase sensitivity for electrochemical detection of dopamine using square wave voltammetry. We plan to incorporate the enzyme glucose oxidase inside of the conductive polymer nanocomposite coating to increase sensitivity for detection of hydrogen peroxide, a correlative biproduct of the glucose oxidase reaction. This technology has the possibility to allow for sensitive, real-time detection of glucose concentrations with high temporal resolution. We have successfully optimized the procedure for coating the conductive polymer onto glassy carbon electrodes. This is observed through a significant increase in the average amplitude of the charge current in response to a 1V/s sweep in a cyclic voltammogram. Also observed is a significant decrease in the average impedance at all tested frequencies below 100kHz for the coated glassy carbon electrode compared to the uncoated glassy carbon electrode. This experimental approach was also applied to platinum electrodes and the same results were observed. Experimentation thus far with incorporation of glucose oxidase into the nanocomposite coating has been inconclusive. Further testing of the glucose oxidase to ensure incorporation and viability within the matrixes will be performed by enzyme functionality assays. The technique will then be used to measure glucose concentration against a known concentration to determine accuracy and precision.

Ian Taylor

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