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- All Subjects: Glucose Sensors
Description
In the search for chemical biosensors designed for patient-based physiological applications, non-invasive diagnostic approaches continue to have value. The work described in this thesis builds upon previous breath analysis studies. In particular, it seeks to assess the adsorptive mechanisms active in both acetone and ethanol biosensors designed for breath analysis. The thermoelectric biosensors under investigation were constructed using a thermopile for transduction and four different materials for biorecognition. The analytes, acetone and ethanol, were evaluated under dry-air and humidified-air conditions. The biosensor response to acetone concentration was found to be both repeatable and linear, while the sensor response to ethanol presence was also found to be repeatable. The different biorecognition materials produced discernible thermoelectric responses that were characteristic for each analyte. The sensor output data is presented in this report. Additionally, the results were evaluated against a mathematical model for further analysis. Ultimately, a thermoelectric biosensor based upon adsorption chemistry was developed and characterized. Additional work is needed to characterize the physicochemical action mechanism.
ContributorsWilson, Kimberly (Author) / Guilbeau, Eric (Thesis advisor) / Pizziconi, Vincent (Thesis advisor) / LaBelle, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2011
Description
Volume depletion can lead to migraines, dizziness, and significant decreases in a subject's ability to physically perform. A major cause of volume depletion is dehydration, or loss in fluids due to an imbalance in fluid intake to fluid excretion. Because proper levels of hydration are necessary in order to maintain both short and long term health, the ability to monitor hydration levels is growing in clinical demand. Although devices capable of monitoring hydration level exist, these devices are expensive, invasive, or inaccurate and do not offer a continuous mode of measurement. The ideal hydration monitor for consumer use needs to be characterized by its portability, affordability, and accuracy. Also, this device would need to be noninvasive and offer continuous hydration monitoring in order to accurately assess fluctuations in hydration data throughout a specified time period. One particular method for hydration monitoring that fits the majority of these criteria is known as bioelectric impedance analysis (BIA). Although current devices using BIA do not provide acceptable levels of accuracy, portability, or continuity in data collection, BIA could potentially be modified to fit many, if not all, desired customer specifications. The analysis presented here assesses the viability of using BIA as a new standard in hydration level measurement. The analysis uses data collected from 22 subjects using an existing device that employs BIA. A regression derived for estimating TBW based on the parameters of age, weight, height, sex, and impedance is presented. Using impedance data collected for each subject, a regression was also derived for estimating impedance based on the factors of age, weight, height, and sex. The derived regression was then used to calculate a new impedance value for each subject, and these new impedance values were used to estimate TBW. Through a paired-t test between the TBW values derived by using the direct measurements versus the calculated measurements of impedance, the two samples were found to be comparable. Considerations for BIA as a noninvasive measurement of hydration are discussed.
ContributorsTenorio, Jorge Antonio (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
The action/adventure game Grad School: HGH is the final, extended version of a BME Prototyping class project in which the goal was to produce a zombie-themed game that teaches biomedical engineering concepts. The gameplay provides fast paced, exciting, and mildly addicting rooms that the player must battle and survive through, followed by an engineering puzzle that must be solved in order to advance to the next room. The objective of this project was to introduce the core concepts of BME to prospective students, rather than attempt to teach an entire BME curriculum. Based on user testing at various phases in the project, we concluded that the gameplay was engaging enough to keep most users' interest through the educational puzzles, and the potential for expanding this project to reach an even greater audience is vast.
ContributorsNitescu, George (Co-author) / Medawar, Alexandre (Co-author) / Spano, Mark (Thesis director) / LaBelle, Jeffrey (Committee member) / Guiang, Kristoffer (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Research concerning increased sensitivity and accurate glucose sensors have been on the forefront of diabetes mellitus. In this study, Electroactive Poly-Amidoamine Polymer (EPOP) was studied to determine if it can be used as a biocompatible electrode, with known redox mediators to determine if it can transfer its own electrons or amplify signal, and if signal is amplified when using an Ag/AgCl working electrode. From the results, it was determined that EPOP is neither a redox mediator, since it cannot transfer its own electrons, nor an electron mediator, since it does not amplify measured current at a specific voltage. Rather, it behaves as an electron sink capacitor with inconsistent behavior when Ag/AgCl is used as the working electrode with the redox mediator alone or with the redox mediator using in combination with glucose oxidase (GOx) and glucose. This was validated using AC-Impedance which gave a -3.3999 slope for isolated 0.05 g/mL EPOP in solution and R2 value of 0.992 displaying it had more capacitor-like behavior compared to resistor-like behavior. For this reason, EPOP was infused into a carbon screen-printed electrode by adding it dissolved and undissolved at two levels into carbon ink. The effectiveness of this electrode was tested using a potentiostatic CV. For the 0.1 g/mL EPOP dissolved in carbon ink, the reduction voltage peak (0.18 V) was found to be slightly higher than a GDE (0.14 V); however, the measured current was found to be 1.57 times the amplitude of a GDE. When 0.05 g/mL EPOP in PBS dissolved in graphite ink was used to detect glucose as the working electrode, there was increased signal amplification, and therefore, increased sensitivity to glucose when using EPOP infused electrodes. This offers promising results for disposable glucose sensors.
ContributorsKapadia, Meera Vipul (Author) / LaBelle, Jeffrey (Thesis director) / Islam, Rafiqul (Committee member) / Honikel, Mackenzie (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
A point of care glucose sensor using electrochemical impedance spectroscopy (EIS) with a glutaraldehyde-linked enzyme shows promise as an effective biosensor platform. This report details the characterization of various factors on optimal binding frequency (OBF) and sensor performance to better prepare the sensor for future experimentation. Utilizing a screen printed carbon electrode, the necessary amount of glucose oxidase was determined to be 10 mg/mL. Binding time trials ranging from 1-3 minutes demonstrated that 1.5 minutes was the optimal binding time. This timeframe produced the strongest impedance response at each glucose concentration. Using this enzyme concentration and binding time, the native OBF of the biosensor was found to be 1.18 Hz using vector analysis. Temperature testing showed little change in OBF in sensors exposed to 4 \u00B0C through 43.3 \u00B0C. Only exposure to 60 \u00B0C resulted in rapid OBF change which was likely due to glucose oxidase becoming denatured. Humidity tests showed little change in OBF and sensor performance between sensors prepared at the humidities of 7.5%, 10.625% and 16.5% humidity. Alternatively, solutions containing common interference molecules such as uric acid, acetaminophen, and ascorbic acid resulted in a highly shifted OBF and drastically reduced signal.
ContributorsMatloff, Daniel (Co-author) / Khanwalker, Mukund (Co-author) / Johns, Jared (Co-author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Lin, Chi (Committee member) / Dean, W.P. Carey School of Business (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
The American Diabetes Association reports that diabetes costs $322 billion annually and affects 29.1 million Americans. The high out-of-pocket cost of managing diabetes can lead to noncompliance causing serious and expensive complications. There is a large market potential for a more cost-effective alternative to the current market standard of screen-printed self-monitoring blood glucose (SMBG) strips. Additive manufacturing, specifically 3D printing, is a developing field that is growing in popularity and functionality. 3D printers are now being used in a variety of applications from consumer goods to medical devices. Healthcare delivery will change as the availability of 3D printers expands into patient homes, which will create alternative and more cost-effective methods of monitoring and managing diseases, such as diabetes. 3D printing technology could transform this expensive industry. A 3D printed sensor was designed to have similar dimensions and features to the SMBG strips to comply with current manufacturing standards. To make the sensor electrically active, various conductive filaments were tested and the conductive graphene filament was determined to be the best material for the sensor. Experiments were conducted to determine the optimal print settings for printing this filament onto a mylar substrate, the industry standard. The reagents used include a mixture of a ferricyanide redox mediator and flavin adenine dinucleotide dependent glucose dehydrogenase. With these materials, each sensor only costs $0.40 to print and use. Before testing the 3D printed sensor, a suitable design, voltage range, and redox probe concentration were determined. Experiments demonstrated that this novel 3D printed sensor can accurately correlate current output to glucose concentration. It was verified that the sensor can accurately detect glucose levels from 25 mg/dL to 400 mg/dL, with an R2 correlation value as high as 0.97, which was critical as it covered hypoglycemic to hyperglycemic levels. This demonstrated that a 3D-printed sensor was created that had characteristics that are suitable for clinical use. This will allow diabetics to print their own test strips at home at a much lower cost compared to SMBG strips, which will reduce noncompliance due to the high cost of testing. In the future, this technology could be applied to additional biomarkers to measure and monitor other diseases.
ContributorsAdams, Anngela (Author) / LaBelle, Jeffrey (Thesis advisor) / Pizziconi, Vincent (Committee member) / Abbas, James (Committee member) / Arizona State University (Publisher)
Created2017