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Developing Aptamer-based Biosensor for Onsite Detection of Stress Biomarkers in Noninvasive Biofluids

Dalirirad, Shima
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595849507754655

Abstract Details

2020, PhD, University of Cincinnati, Arts and Sciences: Physics.
Stress is often called “the silent killer” due to its hidden effects on everything from heart disease to psychological health. Therefore, having a stress-monitoring system would be beneficial for the self-management of mental and physical health of individuals within the stressful environment of today’s world. In this work, we introduce an improved method for developing a robust and user-friendly point of care (POC) diagnostic device to monitor stress and depression biomarkers (cortisol and dopamine) in non-invasive biofluids (sweat, urine, saliva). Paper-based microfluidics represents a desirable substrate for low cost, easy to store/transport/use diagnostic devices that can be used to analyze bodily fluids (such as blood, sweat or urine) for a variety of conditions. The principle of capillary flow in paper-based microfluidics makes the small sample volume move by capillary action without the need for external pumps and are capable of performing multiple assays simultaneously on a single device. Most POC biomarker monitoring tests are based on immunochemical reactions using antibody recognition. The use of aptamer- functionalized gold nanoparticles as a colorimetric method of detection in strip biosensors is an attractive alternative to overcome the limitations of current methods: immunogenicity, sophisticated laboratory techniques, and time-consuming. A paper-based apata-sensor device is designed to detect the levels of stress biomarkers within 10-15 minutes by providing a red band in the test zone of the biosensor. The color intensity in the test zone of the device indicates the target concentration in the sample. The aptamer-based biosensor for the cortisol detection in sweat successfully exhibited a visual limit of detection of 1 ng/mL under optimized condition, readily covering the normal range of free cortisol in sweat (8–140 ng/mL). No significant cross-reactivity to other stress biomarkers was observed. The detection of dopamine in urine has been investigated by using duplex aptamers conjugated to 40-nm AuNP with a 20T linker. The detection method is based on the dissociation of the duplex aptamer in the presence of the dopamine target. The hybridization between the complementary DNA in the test line and the conjugated AuNP-capture DNA produces a red band, whose intensity is related to the target concentration. The minimum detectable concentration by Image J analysis was found to be <10 ng/mL (65.2 nM), while the visual limit of detection is estimated to be ~50 ng/mL (normal range of urinary dopamine 52-480 ng/mL). No cross-reactivity to other stress biomarkers in urine was observed. And finally, non-stressful and noninvasive sampling of saliva compared to blood makes saliva an attractive biological matrix in developing POC devices for biomarker monitoring. The detection of salivary cortisol performed by using the mechanism of duplex DNA dissociation, previously used for dopamine detection in urine. This simple and fast method provides detection in the cortisol range of ~0.5–15 ng/mL, which is in the clinically accepted range for salivary cortisol. The limit of detection is 0.37 ng/mL. The accuracy of this LFA POC was confirmed by ELISA testing. High selectivity was observed for salivary cortisol against other closely related steroids and stress biomarkers present in saliva.
Andrew Steckl, Ph.D. (Committee Chair)
Hans Peter Wagner, Ph.D. (Committee Chair)
Leyla Esfandiari, Ph.D. (Committee Member)
Kay Kinoshita, Ph.D. (Committee Member)
151 p.
Physics
Point Of Care device; Aptamer; Gold Nanoparticles; Stress and depression; Lateral Flow Assay; Biosensor

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Citations

  • Dalirirad, S. (2020). Developing Aptamer-based Biosensor for Onsite Detection of Stress Biomarkers in Noninvasive Biofluids [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595849507754655

    APA Style (7th edition)

  • Dalirirad, Shima. Developing Aptamer-based Biosensor for Onsite Detection of Stress Biomarkers in Noninvasive Biofluids. 2020. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595849507754655.

    MLA Style (8th edition)

  • Dalirirad, Shima. "Developing Aptamer-based Biosensor for Onsite Detection of Stress Biomarkers in Noninvasive Biofluids." Doctoral dissertation, University of Cincinnati, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595849507754655

    Chicago Manual of Style (17th edition)

ucin1595849507754655
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This open access ETD is published by University of Cincinnati and OhioLINK.