• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    LED Excitation and Photomultiplier Tube Biasing and Gating Circuitry for Fluorescence Instrumentation

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_13867_sip1_m.pdf
    Size:
    12.74Mb
    Format:
    PDF
    Download
    Author
    Fairbanks, Jerrie Vincent
    Issue Date
    2015
    Keywords
    Instrumentation
    LED
    Photomultiplier
    Spectroscopy
    Time-resolved
    Electrical & Computer Engineering
    Fluorescence
    Advisor
    Powers, Linda S.
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Embargo
    Release after 1-Nov-2015
    Abstract
    Fluorescence technologies have only begun exploiting the transient recording of lifetime-based signals and images for low nanosecond lifetimes, but the method has tremendous potential for scientific and medical applications. Low nanosecond lifetime recording in real-time can enable the tracking of metabolite concentrations in cells and tissues (e.g. cancerous tissues) without introducing foreign substances. It will also enable the tracking of reactive species (e.g. ozone) and intermediate/short-lived states in chemical reactions in the atmosphere. Current techniques all employ laser excitation, but LEDs can also be used which cause considerably less damage to live tissue. We have developed a high speed fluorescence prototype using high intensity LED pulses and novel PMT gating technology. Precision timing circuitry generates tunable width pulse signals which are driven through the LED using a comparator-based push-pull architecture. The timing circuitry also generates PMT gating pulses which are applied to the dynode chain via high voltage operational amplifiers. LED pulses with fall times (99%) as short as 2ns and PMT gating times (10% to 90%) of 3.6ns have been achieved. The prototype has been used to successfully measure the fluorescent lifetimes of Alexa Fluor 610X dye (1.7ns and 4.7ns) and riboflavin (4.5ns). Lifetimes of acridine orange were measured as follows: alone (2ns), in solution with ssDNA (3.7ns), in solution with dsDNA (5.8ns), and in solution with dsRNA (5.9ns). Finally, dsRNA was heated and allowed to cool revealing lifetimes that started at 3.7ns when hot and increased to nearly 5ns when cool.
    Type
    text
    Electronic Dissertation
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Electrical & Computer Engineering
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.